2{41 -Deoxyaminoglycosides and 2{41 -epi-amino-3{41 -desamino derivatives thereof, methods for their manufacture and novel intermediates useful therein

ABSTRACT

Novel 2&#39;&#39;&#39;&#39;-deoxy-pseudotrisaccharide aminoglycoside antibacterials include 2&#39;&#39;&#39;&#39;-deoxygentamicins and related 2&#39;&#39;&#39;&#39;deoxyaminoglycosides and 2&#39;&#39;&#39;&#39;-epi-amino-3&#39;&#39;&#39;&#39;-desamino derivatives thereof. Aminoglycoside antibiotics and antibacterially active derivatives thereof having a 2&#39;&#39;&#39;&#39;-hydroxyl group and per-Nsubstituted amino functions are converted to a 2&#39;&#39;&#39;&#39;-Ohydrocarbonsulfonyl ester and thence to a 2&#39;&#39;&#39;&#39;-lower alkylthio2&#39;&#39;&#39;&#39;-deoxy derivative or to a 2&#39;&#39;&#39;&#39;-epi-sulfhydryl-2&#39;&#39;&#39;&#39;-deoxy derivative, followed by treatment thereof with a reductive desulfurization agent to obtain a 2&#39;&#39;&#39;&#39;-deoxyaminoglycoside derivative. In an alternate process, N-protecting groups are removed from a 2&#39;&#39;&#39;&#39;-O-hydrocarbonsulfonylaminoglycoside derivative followed by ring closure thereof to form a 2&#39;&#39;&#39;&#39;-deoxy-3&#39;&#39;&#39;&#39;-desamino-2&#39;&#39;&#39;&#39;,3&#39;&#39;&#39;&#39;epimino-aminoglycoside; hydrogenolysis of the foregoing or treatment thereof with a sulfur nucleophile followed by desulfurization produces a product mixture comprising a 2&#39;&#39;&#39;&#39;deoxyaminoglycoside and a 2&#39;&#39;&#39;&#39;-deoxy-2&#39;&#39;&#39;&#39;-epi-amino-3&#39;&#39;&#39;&#39;-desaminoaminoglycoside.

United States Patent [191 Daniels Nov. 18, 1975 154] 2'-DEOXYAMINOGLYCOSIDES AND 2 -EPI-Al\ HNO-3 -DESAMINO DERIVATIVESTHEREOF, METHODS FOR THEIR MANUFACTURE AND NOVEL INTERlV[EDIATES USEFULTHEREIN [75] Inventor: Peter J. L. Daniels, Cedar Grove,

[73] Assignee: Schering Corporation, Kenilworth,

[22] Filed: Oct. 24, 1972 [21] Appl. No.: 300,083

[52] US. CL... 260/210 AB; 260/210 K; 260/210 R;

424/180 [51] Int. Cl. C0711 15/22 [58] Field of Search 260/210 AB, 210 K[56] References Cited UNITED STATES PATENTS 3,268,508 8/1966 Sugazawa eta1 260/210 K 3,651,042 3/1972 Marquez et a1. 260/210 AB 3,828,021 8/1974Beattie et a1. 260/210 AB Primary ExaminerJohnnie R. Brown Attorney,Agent, or FirmMary S. King [5 7] ABSTRACT Novel2"-deoxy-pseudotrisaccharide aminoglycoside antibacterials include2"-deoxygentamicins and related 2"-deoxyaminoglycosides and2"-epi-amin0-3- desamino derivatives thereof.

Aminoglycoside antibiotics and antibacterially active derivativesthereof having a 2"-hydroxyl group and per-N-substituted amino functionsare converted to a 2"-O-hydrocarbonsulfonyl ester and thence to a2-lower alkylthio-2-deoxy derivative or to a 2-epi-sulfhydryl-2"-deoxyderivative, followed by treatment thereof with a reductivedesulfurization agent to obtain a 2-deoxyaminoglycoside derivative.

36 Claims, N0 Drawings I 2 '-DEOXYAMINOGLYCOSIDES AND 2 '-EPI-AMINO-3'-DESAMINO DERIVATIVES THEREOF, METHODS FOR THEIR MANUFACTURE AND NOVELINTERMEDIATE USEFUL THEREIN FIELD OF THE INVENTION This inventionrelates to novelcoinpositions of matter, to methods for theirmanufacture and to novel intermediates useful therein.

More specifically, this invention relates to novel 2"-deoxyaminoglycosides, 2 -deoxy-2 -epimethylamino-3"-desmethylamino-aminoglycosides and 2 deoxy-Z -epiamino 3"-desamino-aminoglycosides having antibacterial activity, to methods fortheir manufacture and to novel intermediates useful therein.

In particular, this invention relates to novel 2"-deoxygentamicins and2-deoxy derivatives of related aminoglycosides such as2"-deoxysisomicin, 2"-deoxytobramycin, 2"-deoxyverdamicin and 3',4',2-trideoxykanamycin B, and to the 2"-epi-methylamino- 3 '-desmethylamino(or 2 '-epi-amino-3 '-desamino-) derivatives thereof, to methods fortheir manufacture from aminoglycoside antibiotics and antibacteriallyactive derivatives thereof having a 2"-hydroxy group, and to novelintermediates useful therein, including 2"-O- hydrocarbonsulfonylandper-N-substituted-2"-O- hydrocarbonsulfonyl-derivatives,per-N-substituted- 2 '-alkythio-2 '-deoxy derivatives, 2'-epi-sulfhydryl- 2"-deoxy-and monoandper-N-substituted-2"-episulfl1ydryl-2 -deoxy-derivatives, 2 -deoxy-3-desm'ethylamino-2 ",3 '-N-methylepimino (or 2"-deoxy-3 desamino-2 ,3-epimino) derivatives, 2' '-deoxy-3 -desamino-(ordesmethylamino)-2"-epi-amino (or 2"- epi-N-methylamino-3'-epi-hydrocarbonthio (and acylthio)-derivatives and theirper-N-substituted derivatives, 2"-deoxy-2"-hydrocarbonthio(andacylthio)- derivatives and their per-N-substituted derivatives, andper-N-substituted-2-deoxy derivatives of gentamicin (particularly ofgentamicin C gentamicin C andgentamicin C and of sisomicin, tobramycin,verdamicin and 3,4'-dideoxykanamycin B, as well as cyclic ketals andacetals of the foregoing.

PRIOR ART It is known that certain bacteria are resistant toaminoglycoside antibiotics and that this resistance can be mediated byinfectious R factors which are capable of enzymatic modifications of theantibiotics, producing derivatives of the antibiotics which are inactiveagainst the bacteria. It is known, for example, that N- By my invention,2-deoxy derivatives andv '2 deoxy-2 -epi-methylamino-3 -desinethylaminoderivatives' of gentamicin andof related aminoglycoside an-'tibioticsand derivativesthereof are prepared which have anti-bacterialactivity,-t he preferred compounds of which, advantageously, are activeagainst bacteria resistant to gentamicin, particularly against theR-factor-carrying. strains of bacteria which adenylylate gentamicin. Bymy invention, therefore, 2-deoxyaminoglycoside antibiotic derivativesare prepared which possess an improved antibacterial spectrum over thatpossessed by the parent aminoglycoside antibiotic or derivative thereofhaving a 2"-hydroxyl function.

SUMMARY OF INVENTION lating R-factor-carrying .strains of bacteria whichare resistant to gentamicin C.

Another composition-of-matter aspect of this invention relates tochemical compounds valuable as intermediates in the preparation of the2"'--deoxyaminoglycoside antibacterials of this invention, saidintermediates having a pseudotrisaccharide aminoglycoside structure andbeing derived from known aminoglycoside antibiotics having a 2"-hydroxyfunction and antibacterially active derivatives thereof. Included are2')\ -O-hydrocarbonsulfonyl aminoglycoside derivatives as well as2"-O-hydrocabonsulfonyl derivatives wherein all the primary andsecondary amino groups are protected by a member selected from the groupconsisting of lower alkanoyl, carbobenzyloxy, lower thioalkanoyl,

, thioaroyl, and lower alkylthiocarbamoyl, and wherein protectableneighboring primary and secondary hydroxyl groups are optionallyconverted to a cyclic ketal or acetal selected from the group consistingof alkylidene, cycloalkylidene and aralkylidene, or wherein any primaryhydroxyl group is converted to a triphenylmethyl ether derivative or isconverted to a hydrocarbonsulfonate ester. Other intermediates include2"- 'epi-sulfl1ydryl-2-deoxy derivatives having free amino and freehydroxyl groups as well as those having protected amino and protectedhydroxyl groups; 2"- deoxy-2 '-hydrocarbonthio(or 2-acylthio)derivatives and the per-N-substituted derivatives thereof; per-N- Udeoxy-3 "-des methylamino(or substitute d-2' epi-benzylthio-2 -deoxyderivatives; 2"-d eoxy-3-desmethylamino (or desamino)-2"-epi-N-methylamino-(or epi-amino)-3 '-epi-hydrocarbonthio-(orepi-acylthio)-derivatives and their per-N- substituted derivatives; 2'-deoxy-3 -desmethylamino- 2",3"-N-methylepiminof or 2"-deoxy-3-desamino-2 ,3 epimino derivatives; per-N-substituted-Z deoxyaminoglycosides; andper-N-substituted'-2"- desamino )-2 '-epi-N- methylami'no' (orepi-amino)-aminoglycosides; including acetals and ketals of theforegoing as well as acetals and ketals of the 2'-deoxyaminoglycosideantibacteri- 3 als of this invention. Preferred intermediates are thosederived from the aminoglycoside antibiotic precursors of the preferred2-deoxyaminoglycosides of this invention, e.g. those derived fromgentamicin C gentamicin C gentamicin C sisomicin, and verdamicin.

The processes of this invention are, in general, directed toward theremoval of the 2"-hydroxyl group in an aminoglycoside antibiotic orantibacterially active derivative thereof to obtain the corresponding,novel 2"-deoxyaminoglycoside derivative having antibacterial activity.

Briefly, in one process, the 2"-hydroxyl group of the aminoglycoside isconverted to a 2-hydrocarbonsulfonate ester which, in turn is convertedto a 2"-deoxy- 2"-thiol (or epithiol) derivative which is thendesulfurized to form a 2"-deoxyaminoglycoside of this invention (seeChart A hereinbelow).

More specifically, by this process, an antibacterially activeaminoglycoside having a 2"-hydroxy function, the primary and secondaryamino groups of which are protected by a member selected from the groupconsisting of lower alkanoyl, lower thioalkanoyl, thioaroyl, andloweralkylthiocarbamoyl, and protectable primary and secondary hydroxylgroups of which are converted to an O-protecting function selected fromthe group consisting of a triphenylmethyl ether (also called a tritylether) of a primary hydroxyl group and a cyclic ketal or cyclic acetalof protectable, neighboring hydroxyl groups, is treated with ahydrocarbonsulfonyl halide having up to eight carbon atoms in a tertiaryamine, wherey is formed a 2-O-hydrocarbonsulfonylaminoglycosideintermediate which is then converted to a 2"-thio-2"-deoxyaminoglycosideintermediate. This conversion is effected by treating a per-N- loweralkanoyl-2 -O-hydrocarbonsulfonylaminoglycoside with analkali metal saltof a lower alkylthiol in an anhydrous, polar, non-hydroxylic solvent,optionally followed by acid hydrolysis of any O-protecting functionspresent, whereby the 2"-thio-2"-deoxyintermediate formed is a 2"-loweralkylthio-2"-per-N-lower alkanoylaminoglycoside; alternatively saidconversion is effected by heating a member selected from the groupconsisting of a per-N-thio-alkanoyl-2"-O-hydrocarbonsulfonylaminoglycoside, aper-N-thioaroyl-2"-O-hydrocarbonsulfonylaminoglycoside, and aper-N-alkylthiocarbamoyl-2"-O-hydrocarbonsulfonylaminoglycosideintermediate in an aqueous medium at temperatures in the range of fromabout 25C to about 150C followed by removal of any sulfur-containingamino protecting groups in the thereby formed 2' '-epi-sulfhydryl-2-deoxyaminoglycoside after otpional acid hydrolysis of any protectinggroups present, whereby is formed a 2"-thio-2-deoxy intermediateselected from the group consisting of a 2-epi-sulfhydryl-2 -deoxyaminoglycoside, a 2 -epi-hydrocarbonthio-2-deoxy-3"-N-lower alkanoyl (oraroyl or N-lower alkyl carbamoyl)-amino-glycoside, said hydrocarbonhaving up to 8 carbon atoms, and a 2"-epicarboxymethylenethio-Z -deoxy-3'-N-lower alkanoyl (or N-lower alkylcarbamoyl)-aminoglycoside; removalof the 2"-thio function of said 2-thio-2"-deoxyaminoglycosideintermediate is then effected, optionally after all free amino andsulfhydryl functions are acylated (e.g. acetylated) by treatment with areductive desulfurization agent selected from the group consisting ofRaney Nickel and aluminum amalgam, followed by alkaline hydrolysis ofany amino protecting groups,

4 whereby is obtained a 2"-deoxyaminoglycoside of this invention.

In the foregoing process, the sulfur containing groups may be removedfrom said 2"-thio-2"-deoxy intermediate by alkaline hydrolysis whichwill remove all the N-protecting groups; or, alternatively, byS-alkylating the 2-epi-sulfhydryl-2"-deoxyper-N-thioalkanoyl (orthioaroyl or N-alkylthio carbamoyl)-aminoglycoside Another process ofthis invention comprises treating an aminoglycoside antibiotic orantibacterially active derivative thereof having a 2-hydroxy functionand a 3"-primary or secondary amino function, the primary and secondaryamino groups of which are protected by carbobenzyloxy groups, and anyprotectable primary and secondary neighboring hydroxyl groups of whichare converted to a cyclic acetal or ketal function, with ahydrocarbonsulfonyl halide having up to eight carbon atoms in a tertiaryamine; removing the carbobenzyloxy protecting groups by treating the2"-O- hydrocarbonsulfonyl-per-N-carbobenzyloxyaminoglycoside therebyformed with hydrogen in the presence of a catalyst or by cleavage withan alkali metal in liquid ammonia; converting the resulting 2"-O-hydrocarbonsulfonylaminoglycoside to the corresponding 2 -deoxy-3'-desamino-2 ,3 '-epimino intermediate by means selected from the groupconsisting of spontaneous formation, and heating at temperatures in therange of from about 25 to about C in lower alkanol alone or in thepresence of an alkali metal salt of a lower alkanol; treating thecorresponding 2"-deoxy- 3 -desamino-2 ,3 '-epimino-aminoglycosidethereby formed with hydrogen in the presence of a catalyst or with asulfur nucleophile, optionally followed by conversion of the resultingproduct mixture comprising a 2-deoxy-2"-thioland a2"-deoxy-2-epi-amino-3"- desamino-3"-epi-thiointermediate to aper-N-substituted derivative thereof, followed by desulfurization (egwith Raney Nickel or aluminum amalgum), removal of any N-protectinggroups with base and removal ofany acetal or ketal functions with acid;whereby is obtained a 2 '-deoxyaminoglycoside and the corresponding 2'-deoxy-2 -epi-amlno-3 desaminoaminoglycosides, respectively. Separationof the product mixture may be carried out either before or after removalof the N-protecting groups.

GENERAL DESCRIPTION OF THE INVENTION Antibacterial Composition-of-MatterAspect Included among the antibacterially active composi-- wherein R isa member selected from the group consisting of amino and hydroxy; R andR are each members selected from the group consisting of hydrogen andhydroxy; R is a member selected from the group consisting of hydrogenand methyl; R is a member selected from the group consisting of hydroxy,amino and methylamino; R and R are each members selected from the groupconsisting of hydrogen and methyl; and R is a member selected from thegroup consisting of hydrogen and hydroxymethyl.

The anti-bacterially active 3"-desamino-2"-epiamino derivatives of the2-deoxyaminoglycosides of above formulae 1(a) and [(b) are thus definedby following formulae II(a) and Il(b):

wherein R R R R R R R and R are as defined hereinabove for formulae l(a)and [(b).

The compounds'defin ed by the structural formulae in this specificationand in the claims are numbered in accordance with standard practice foraminoglycosides such as disclosed hereinabove. The terminal glycosiderings are numbered according to usual carbohydrate nomenclature withprime numbers allocated to the 2- amino, 6-amino or 2,6-diaminosugarring, double prime numbers allocated to the 3-amino-sugar ring andregular numbers assigned to the 2-deoxystreptamine ring with the carbonatom to which the 3-aminosugar unit is attached designated as position6.

The stereoconfigurations of the 2-deoxyaminoi R NH NH 5 2 M2 NR2 0 N3 R"R" S HO o g CH3 H no II(a.) 11(1)) glycosides of formulae 1(a), l(b),II(a) and II(b) are the same as those of their corresponding 2"-hydroxyprecursors. Compounds designated as 2-epi-derivatives have substituentsat the 2"-position which are of opposite stereochemistry to those of the2"-hydroxyl groups of the antibiotic precursors. In this specificationand in the claims, while the structural formulae of the compounds ofthis invention will be designated in planar fashion as indicatedhereinabove; it is to be understood, however, that thestereoconfiguration of the compounds defined thereby is the same as thatof their 2"- hydroxyaminoglycoside precursors.

The anti-bacterially active compounds of this invention as defined byformulae Ia and lb include the following:

2-deoxygentamicin A (a compound of formula Ia wherein R is amino, R Rand R are each hydroxy, R R and R are each hydrogen, and R is methyl);

2-deoxygentamicin B (a compound of formula la wherein R R and R are eachhydroxy, R is amino, R and R are each hydrogen, and R and R are eachmethyl);

2-deoxygentamicin B, (a compound of formula Ia wherein R R and R areeach hydroxy, R is amino, 6R R and R are each methyl, and R ishydrogen);

2-deoxygentamicin X (a compound of formula Ia wherein R is amino, R Rand R are each hydroxy, R and R are each hydrogen and R and R are eachmethyl);

2"-deoxy-Antibiotic JI-20-A (a compound of formula Ia wherein R and Rare each amino, R and R are each hydroxy, R and R are each hydrogen, andR and R are each methyl);

2"-deoxy-Antibiotic Jl-20-B (a compound of formula Ia wherein R and Rare each amino, R and R are each hydroxy, R R and R are each methyl, andR is hydrogen);

2"-deoxytobramycin (a compound of formula la wherein R and R are eachamino, R R R and R are each hydrogen, R is hydroxy, and R ishydroxymethyl); and

3,4,2"-trideoxykanamycin B (a compound of formula la wherein R and R areeach amino, R R R R and R are each hydrogen, and R is hydroxymethyl).

A preferred group of compounds of my invention include those defined byformula lb. Also preferred are compounds of formula Ia when R is amino,R R and R are each hydrogen, R and R are each methyl, R is hydrogen ormethyl, and R is amino or methylamino, said compounds being defined byfollowing formula Ia and include the non-toxic, pharmaceuticallyacceptable acid addition salts thereof:

NHC H3 wherein R and R are as defined hereinabove for the compounds offormulae 1(a) and l(b).

Included within this preferred group of compounds are:

2-deoxygentamicin C, (compound of formula Ia wherein R is methyl and Ris methylamino);

2"-deoxygentamicin C (compound of formula 1,,

wherein R is hydrogen and R is amino); 2"-deoxygentamicin C (compound offormula 1,,

wherein R is methyl and R is amino; the stereochemistry at 06' being R);

2"-deoxygentamicin C (compound of formula l wherein R is methyl, R isamino, the sterochemistry at C-6 being S);

2"-desoxysisomicin (a compound of formula Ib wherein R is hydrogen); and

2"-deoxyverdamicin (a compound of formula Ib wherein R is methyl).

Exemplary of the antibacterially active compounds of this invention asdefined by formula II(a) and II(b) are2"-deoxy-3"-desamino-2"-epi-amino-aminoglycosides such as:

2' '-deoxy-2 -epi-methylamino-3 '-desmethylaminogentamicin C (a compoundof formula II(a) wherein R is amino, each of R R and R are hydrogen,each of R R and R are methyl,-

of R R, and R are hydrogen, and each of R R and R are methyl);

2 -deoxy-2 '-epi-methylamino-3 -desmethylaminosisomicin (a compound offormula ll(b) wherein R is hydrogen);

2 '-deoxy-2 '-epi-methylamino-3 '-desmethylaminoverdamicin (a compoundof formula ll(b) wherein R is methyl);

2 '-deoxy-2 '-epi-amino- 3 '-desaminotobramycin (a compound of formulalI(a) wherein each of R and R are amino, each of R R R and R arehydrogen, R is hydroxy and R is hydroxymethyl); and

3 ,4 ,2 -trideoxy-2 -epi-amino-3 -desaminokanamycin B (a compound offormula Il(a) wherein each of R and R are amino, each of R R R R and Rare hydrogen and R is hydroxymethyl).

by formulae I(a), I(b), II(a) and II(b) which are made according toknown procedures such as by neutralizing the free base with theappropriate acid to below about pH 7.0 and, advantageously, to about pH2 to pH 6. Suitable acids for this purpose include acids such ashydrochloric and sulfuric.

The physical embodiments of the acid addition salts of the2"-deoxyaminoglycosides of this invention are characterized by beingwhite solids which are soluble in water and alcohols, e.g. methanol,ethanol, and the like, and are insoluble in most polar and non-polarorganic solvents.

The compounds of this invention as defined by formulae l(a), I'(a),I(b), [1(a) and Il(b) and their nontoxic pharmaceutically acceptableacid addition salts, in general, exhibit anti-bacterial activity andusually have a spectrum of activity similar to that of their 2"- hydroxyprecursors. Of these, some also exhibit antiprotozoal, anti-amoebicand/or anthelmintic properties. The preferred 2-deoxyaminoglycosides ofmy invention (e.g. 2"-deoxygentamicin C 2"-deoxygentamicin C a,2"-deoxygentamicin C 2"-deoxygentamicin C a, 2-deoxysisomicin and2"-deoxyverdamicin) are broad spectrum anti-bacterial agents, beingactive against gram positive bacteria (e.g. Staphylococcus aureus) andgram negative bacteria (e.g. Escherichia Cali and Pseudomonasaeruginosa) as determined by standard dilution tests mentionedhereinbelow. Advantageously, my preferred compounds are also cidalagainst the R-factor-carrying strains of bacteria which adenylylategentamicin; thus, my preferred 2"-deoxyaminoglycosides exhibit animproved antibacterial spectrum over that possessed by the 2"-hydroxyprecursor.

Compounds Useful as Intermediates Compounds of this invention useful asintermediates are novel derivatives of known aminoglycoside antibioticshaving a 2"-hydroxy function including compounds selected from the groupconsisting of 2"-O- hydrocarbonsulfonyl derivatives such as defined bystructural formula IlI(a) and llI(b) shown hereinbelow and the cyclicketal and cyclic acetal derivatives thereof:

H R' NHX Ex 5 NHX X CH

S 0 M &3

oso m III(b) i N X,

X being as defined hereinabove; R R R5, R3", 4" and R being as definedfor formula 1(a).

The 2"-O-hydrocarbonsulfonyl derivatives contemplated are those derivedfrom hydrocarbonsulfonic acids having up to 8 carbon atoms includingethanesularylthiocarboxylic acids having up to 8 carbon atoms includingthiobenzoyl, thiotoluyl and thiomesityloyl.

By lower alkyl are contemplated hydrocarbons having up to eight carbonatoms; thus, the radical lower alkylthiocarbamoyl includes radicals suchas ethylthiocarbamoyl, n-propylthiocarbamoyl, n-butylthiocarbamoyl andpreferably, methylthiocarbamoyl.

By protectable neighboring hydroxyl groups are contemplated vicinal andnon-vicinal hydroxyl groups which together will form ketal and acetalfunctions with ketone derivatives and with aldehydes. Exemplary of suchprotectable hydroxyl groups are the 2, 3, 4,- hydroxy groups togentamicin B and 8,, the 4,6'- hydroxy groups in gentamicin A and X andin Antibiotic G-4l8, the 3', 4hydroxy groups in Antibiotics JI- -A andJl-20-B, and the 4,6-hydroxy groups in tobramycin and 3,4'-dideoxykanamycin B.

The cyclic ketal and acetal derivatives of said neighboring protectablehydroxyl groups of this invention include O-alkylidene (e.g.O-iso-propylidene), O- cycloalkylidene (e.g. O-cyclohexylidene) andO-aralkylidene (e.g. O-benzylidene) derivatives.

The preferred intermediates of formula III(a) and III(b) are thosewherein M is methyl, X is a member selected from the group consisting ofacetyl, carbobenzyloxy, thioacetyl, thiobenzoyl and methylthiocarbamoyl,and wherein said derivatives are derived from gentamicin C gentamicin Cgentamicin C gentamicin C sisomicin and verdamicin. Preferredintermediates of formulae III(a) and III(b) include the following per-N-acetyl derivatives wherein M is methyl, X is acetyl, W isN-acetylamino, and wherein R R R R and R are the substituents definedfor the corresponding positions of formula 1(a);

2 -O-methanesulfonyl-l ,3,2,6',3 "-penta-N-acetylgentamicin C (compoundof formula III(a) wherein W is N-acetyl-N-methylamino and R is methyl);

2' -O-methanesulfonyl-l ,3,2 ,6',3 -penta-N-acetylgentamicin C (compoundof formula III(a) wherein W is N-acetylamino and R is hydrog 2'-O-methanesulfonyl-l ,3 ,2 ,6',3 -penta-N-acetyl gentamicin C (compoundof formula III(a) wherein W is N-acetylamino and R is methyl), thestereochemistry at C-6 being R.

2' -O-methanesulfonyl-l ,3,2 ,6',3 "-penta-N-acetylgentamicin C a(compound of formula III(a) wherein W is N-acetylamino and R is methyl,the stereochemistry at C-6 being S);

2-O-methanesulfonyl-l ,3,2 ,6',3 -penta-N-acetyl sisomicin (a compoundof formula III(b) wherein R is hydrogen);

2 -O-methanesulfonyll ,3,2 ,6',3 -penta-N-acetylverdamicin (a compoundof formula III(b) wherein R is methyl).

Other useful intermediates of formulae III (a and b) include thosederived from gentamicin A, gentamicin B, gentamicin B gentamicin X andAntibiotics Jl-20- A, Jl-20-B and G-418 which have protectableneighboring hydroxyl groups converted to a cyclic ketal thereof,preferably the isopropylidene derivative, such as the following:

2''-O-methanesulfonyl-4',6'-O-iso-propylidenel,3,2,3"-tetra-N-acetylgentamicinA (a compound of formula III(a) wherein M is methyl, X is acetyl, W isN-acetylamino, R R and R are each hydrogen, R is methyl, and R R and Ware each hydroxyl groups of which W and R are converted to thecorresponding cyclic O-isopropylidene ketal thereof);

2 -O-methanesulfonyl-2 ,3 (and 3 ,4 )-O-isopropylidene-1,3 ,6',3'-tetra-N-acetylgentamicin B(a compound of formula III(a) wherein M ismethyl, X is acetyl, W is N-acetylamino, R and R are each hydrogen, Rand R are each methyl, and W and R and R are hydroxyl groups convertedto the corresponding 2',3 (and 3',4)-O-iso-propylidene ketal derivativethereof;

2 -O-methanesulfonyl-2 ,3 (or 3 ,4' )-O-iso-propylidenel ,3,6,3"-tetra-N-acetylgentamicin B 2 '-O-methanesulfonyl-4 ,6'-O-iso-propylidenel ,3 ,2 ,3 '-tetra-N-acetylgentamicin X 2'-O-methanesulfonyl-3 ,4-O-iso-propylidenel ,3 ,2 ,6',3-penta-N-acetylantibiotic J I-ZO-A;

2 -O-methanesulfony l-3 ',4-O-iso-p ropylidene- 1,3,2 ,6',3'-penta-N-acetylantibiotic JI-20-B; and2"-O-methanesulfonyl-4,6-O-iso-propylidene- 1 ,3,2 ,3 -tetra-n-acetylantibiotic 6-4 1 8.

In addition to the foregoing, valuable intermediates of the invention asdefined by formula III(a) and III(b) are per-N-carbobenzyloxy,per-N-thioacetyl, per-N-thiobenzoyl and per-N-methyl-thiocarbamoylderivatives of the 2-O-methanesulfonyl esters of gentamicin C gentamicinC gentamicin C gentamicin C sisomicin and verdamicin; the4,6-O-iso-propylidene-per-N- carbobenzyloxy, the4,6'-O-iso-propylidene-per-N-thioacetyl, the4',6-O-iso-propylidene-per-N-thiobenzoyl and the4',6-O-iso-propylidene-per-N-methylthiocarbamoyl derivatives of the2"-O-methanesulfonyl esters of gentamicin A, gentamicin X and ofAntibiotic G- 418; the 3,4'-O-iso-propylidene-per-N-carbobenzyloxy, the3,4'-O-isopropylidene-per-N-thioacetyl, the3,4-O-iso-propylidene-per-N-thiobenzoyl and the 3,4-O-iso-propylidene-per-N-methylthiocarbamoyl derivatives of the2-O-methanesulfonyl esters of Antibiotic JI-20-A and JI-20-B; as well asproduct mixtures comprising the 2',3(and 3,4)-O-iso-propylidene-per-N-carbobenzyloxy, the 2,3 (and3',4')-O-iso-propylidene-per-N-thioacetyl, the 2,3' (and3',4')-O-isopropylidene-per-N-thiobenzoyl and the 2',3' (and 3',-4)-O-iso-propylidene-per-N-methylthiocarbamoyl derivatives of the2"-O-methanesulfonyl esters of gentamicin B and gentamicin B Alsoincluded within this invention are 2"-O- hydrocarbonsulfonyl derivativesof formulae III(a and b) of 2"-hydroxyaminoglycoside antibiotics havingprimary hydroxyl groups wherein said primary hydroxyl groups is eitherprotected by an ether derivative, e.g. an O-triphenylmethyletherderivative, or the primary hy- 13 droxyl group is also converted to itshydrocarbonylsulfonyl ester. Typical derivatives of this group are:2-O-methanesulf0nyl-6"-O-triphenylmethyl- 1,3 ,2,6 ,3penta-N-thioacetyltobramycin, 2"-Omethanesulfonyl-6-O-triphenylmethyl-1,3 ,2',6' ,3 -penta-N-thioacetyl-3 ,4-dideoxykanamycin B,6'-O-triphenylmethyl-2"-Omethanesulfonyl-l ,3,2',-

3"-tetra-N-thioacetylgentamicin A, 6-O-triphenylmethyl-2O-methansulfonyl-l ,3 ,2

3"-tetra-N-thioacetylgentamicin X acetyltobramycin, and

acetyl-3 ',4-dideoxykanamycin B.

The 2"-O-hydrocarbonsulfonyl derivatives of formulae Ill(a and b) arevaluable as intermediates in all the processes of this invention. Asdescribed hereinbelow in detailed description of the processes, they areconveniently prepared from the corresponding 2"-hydroxyper-N-substitutedaminoglycosides having protectable hydroxyl groups derivatized(preferably as the O-isopropylidene derivative) by treatment thereofwith a hydrocarbonylsulfonyl halide (preferably methanesulfogen andhydroxy; R R and R are each a member selected from the group consistingof hydrogen and methyl; and the cyclic ketal and cyclic acetalderivatives thereof.

Preferred derivatives defined by formulae IV(a) and IV(b) are thosewherein alkyl is ethyl and wherein Y is acetyl. Preferred intermediatesof this invention thus include: i

verdamioin. Other useful 2"-alkylthio-2"-deoxy derivatives of FormulaeIV(a and b) include:

Product mixture comprising 2"-ethylthio-2"-deoxy- 2',3)-O-iso-propylidenel ,3 ,6,3 -tetra-N-acetylnyl chloride) in a tertiaryamine (preferably pyridine). 25 gentamicin Other useful intermediates ofthis invention include product mixture comprising 2"-loweralkylthio-2-deoxy derivatives of 2-hydrox- 2I,3'(and o yaminoglycosideantibiotics selected from the group N acetylgemamicin Bl; consisting ofcompounds defined by formulae IV (a and r u l i b) Show herembebwl1,3,2',6'3"-penta-N-acetyl Antibiotic JI-ZO-A;

H H 2 my 2 R C- -=-T R *NHY NHY o O NHY 15 OH OH a NH! 0 Ra -O HO '-o XY ml 1R5 crr wi H3 S-Alkyl dmwl IV(b) wherein alkyl is a hydrocarbonhaving up to 8 carbon atoms; Y is lower alkanoyl; T is a member selectedfrom the group consisting of hydroxy and NHY, Y being as definedhereinbelow; T is a member selected from the group consisting ofhydroxy. NHY and Y being as defined hereinabove; R and R, are eachmembers selected from the group consisting of hydro- Other novelintermediates of this invention include R and R are each hydrogen, and RR and compounds selected from the group consisting of 2- R are eachmethyl), epi-sulfhydryl-2"-deoxy-per-N-substituted derivatives 1, H I, Iof known aminoglycoside antibiotics defined by formu- 2 f Emcetlml laeV(a) and V(b) shown hereinbelow, and cyclic ket- 5 ce y gen 1 a d t l hf; 2"-epi-sulfhydryl-2-deoxy-3"-N-(N-methylcar- H NHZ a R M"NHZ NHZ NHZNHZ

on i on NHZ R; R" O ling Z: #11,? N Rn 3 'SH new v( V(b) wherein Z is amember selected from the group consistbamoyl)-l,3,2,6'-tetra-N-(N-methylthiocarmg of lower thioalkanoyl, thioaroyl andlower alkylthibamoyl)gentamicin C a,

ocarbamoyl, Z is a member selected from the group2"-epi-sulfhydryl-2"-deoxy-3"-N-acetyl-l,3,2,6-

consisting of lower alkanoyl, aroyl and loweralkylcartetra-N-thioacetylgentamicin C bamoyl, U is a member selectedfrom the group con- 2"-epi-sulfhydryl-2"-deoxy-3"-N-(N'-methylcarsistingof hydroxy, N-thioalkanoylamino, N-thibamoyl)-l,3,2,6-tetra-N-(N'-methylthiocarbamoaroylamino andN-alkylthiocarbamoylamino, U is a oyl) gentamicin C member selected fromthe group consisting of hydroxy, p y yl- 0 yy NHZ and 406'-tetra-N-thiobenzoylgentamicin C 2-epi-sulfhydryl-2 '-deoxy-3-N-acetyl-l ,3,2 ',6,- CH3 tetra-N-thioacetylgentamicin C a, 2-epi-sulfhydryl-2 -deoxy-3 '-N-( N '-methylcarbamoyl)-l,3,2',6',-tetra-N-(N'-methylthiocarbamoyl) gentamicin C a, Z being asdefined hereinabove, R R R R R2"-epi-sulfhydryl-2"-deoxy-3"-N-acetyl-l,3,2,6'- and R being as definedfor formula l(a). tetra-N-thioacetylsisomicin (compound of formulaPreferred 2-epi-sulfhydryl-2"-deoxy-per-N-sub- Vb wherein Z isthioacetyl, Z is acetyl, and R is stituted intermediates of formulae V(a and b) are hydrogen),

those wherein the alkanoyl group is acetyl, the aroyl bamoyl )-l ,3,2',6',-tetra-N-(N -methylthiocarbamgroup is benzoyl and the alkyl groupis methyl and wherein said derivatives are derived from gentamicin y l oI C gentamicin C 21, gentamicin C gentamicin C a,2"-epl-sulfhydryl-2"-deoxy:3"-N acetyl-l,3, 9 '9- sisomicin andverdamicin. Preferred intermediates of l- -thlOacetylverdamlcln, andformulae V (a and b) thus include the following: P y y ''-de0Xy-3"-lI-(N'-methylcar- 2-epi-sulfhydryl-2"-deoxy-3"-N-acetyl-tetra-N-thiy 2'4y oacetylgentamicin C, (a compound of formula Va Y Y P P Imd of formulaVb h i Z i hi l Z i acetyl, U i N 1- wherein ZlS methylthlocarbamoyl, Z15 methylcaroacetylamino, U is N-thioacetyl-N-methylamino, bamoyl, and 5is y 3', and 1 and s" are each hydrogen, and s'- Typical intermediatesof formula Va derived from R and and R are each methyl), aminoglycosideshaving protectable hydroxy groups 2"-epi-sulfhydryl-2"-deoxy-3-N-(N-m yconverted to cyclic ketals and acetals are as follows: bamoyl l ,3 ,2,6-tetra-N-( N '-methylthiocarbam- 2 -epi-sulfl1ydryl-2 -deoxy-3'-N-acetyl-4-,6 '-O- y gentamicin 1 compound of f rm Vaiso-propylidene-l,3,2-tri-N-thioacetylgentamicin wherein Z ismethylthiocarbamoyl, Z lS methylcar- A (compound of formula Va wherein Zis thioabamoyl, 2 is N-methylthiocarbamoylamino, s cetyl, Z is acetyl, Uis N-thioacetylamino, R is is N-methylthiocarbamoyl-N-methylamino, Rhydroxy, R ,R and R are each hydrogen, and

17 18 R and U together represent iso-propylidenebamoyl when L is benzyland R R R and R R dioXy), R R and R are as defined hereinabove for for-2 '-epi-sulfhydryl-2 '-deoxy-3 -N-(N -methylcarmula la,

bamoyl)-4',6'-O-iso-propylidene-l,3,2'-tri-N-(N' Intermediates definedby formula VI (21 and b) methylthiocarbamoyl) gentamicin A, 5 wherein Land Z" are each hydrogen, include the fol- 3 ,4) O-iso-propylidene-l ,3,6 '-tri-N-thioacetyl- 2 -epi-sulfhydryl-2 '-deoxygentamicin Cgentamicin B, 2"-epi-sulfhydryl-2"-deoxygentamicin C a,

2' '-epi-sulthydryl-2 '-deoxy-3 -N-(N -methylcar- 2 '-epi-sulthydryl-2'-deoxygentamicin C bamoyl)-2,3 (and 3',4)-O-iso-propylidene 102"-epi-sulfhydryl-2"-deoxygentamicin C a,

1,3 ,6 -tri-N-(N'-methylthiocarbamoyl )-gentamicin 2 '-epi-sulfhydryl-2-deoxysisomicin, B 2 -episulfhydryl-2 -deoxyverdamicin,

2' -epi-sulfl1ydryl-2 -deoxy-3 '-N-benzoyl-4,6-O- 2 '-epi-sulfhydryl-2-deoxytobramycin,

isopropylidenel ,3 ,2 '-tri-N-thiobenzoylgentamicin 2' -epi-sulfhydryl-3,4 ,2' '-trideoxykanamycin B;

2, 2"-epi-sulfhydryl-2"-deoxygentamicin A,

2"-epi-sulfhydryl-2"-deoxy-3"-N-acetyl-3,4-O-iso- 2"-e ilfh d l-2"-de xgema i i B,

propylidene-l ,3 ,2',6'-tetra-N-thioacetyl-Antiobi- 2 '-epi-sulfhydryl-2'-deoxygen[amicin B1, otic Jl--A, and2"-epi-sulfhydryl-2"-deoxygentamicin X 2 '-epi-sulfhydryl-2 '-deoxy-3-N-methylcarbam0yl- 2 -epi-sulfhydryl-2 '-deoxy-Antibiotic J I-20-A,

3,4-O-iso-propylidene-l,3,2',6-tetra-N-(N'- 202"-epi-sulfl1ydryl-2"-deoxy-Antibiotic Jl-20-B, and methylthiocarbamoyl)-Antibiotic J I-20-B, 2 '-epi-sulfhydryl-2 -deoXy-Antibiotic G-4 l 8.

2"-epi-sulfhydryl-2"-deoxy derivatives of formulae V (a and b) arevaluable as intermediates in a pro- The above compounds of formulae Vl(a and b) cess of this invention as described in detail hereinwherein Lis hydrogen are conveniently prepared from below. In brief, thecompounds of Va and Vb are the corresponding per-N-substitutedderivatives deconveniently prepared by heating the correspondfined byformulae V (a and b) via alkaline hydrolysis ing2"-O-hydrocarbonsulfonyl derivatives of forthereof at high temperatures(e.g. 120C) for long perimulae III (a and b) when X is thioalkanoyl,thioarods of time (e.g. 96 hours) in a sealed tube. oyl orN-alkylthiocarbamoyl, in an aqueous me- Other intermediates defined byformulae Vl (a and dium. b) are 2"-epi-benzylthioderivatives wherein Lis benzyl Other useful intermediates include 2"-epi-sulfhydryland Z" islower alkanoyl, aroyl or alkylcarbamoyl in- 2"-deoxy,2-epi-benzylthio-2"-deoxy and 2"-epi-carcluding the following:boxymethylenethio-2 -deoxy 3 -N-substituted deriva- 2 '-epi-benzylthio-2-deoxy-3 '-N-acetylgentamicin tives defined by the following formulaeVla and Vlb: C

i H R SMC 2 NE R' C 6 N12 R", ""IT O u 1 rr I NR5 3 3 H0 L VI(b) whereinL is a member selected from the group consist-2"-epi-benzylthio-2"-deoxy-3"-N-acetylgentamicin ing of hydrogen andbenzyl; Z" is a member selected C a,

from the group consisting of hydrogen when L is hydro-2"-epi-benzylthio-2"-deoxy-3"-N-benzoylgentamigen, and of loweralkanoyl, aroyl and lower alkylcarcin C2,

19 2 -epi-benzylthio-2 -deoxy-3 -N-acetylgentamicin C28,2"-epi-benzylthio-2-deoxy-3"-N-acetylsisomicin and 2 -epi-benzylthio-2-deoxy-3 -N-acetylverdamicin.

The 2"-epi-benzylthio-2"-deoxy-3-N-alkanoyl (or aroyl or alkylcarbamoyl)derivatives of formulae VI (a and b) are prepared from the2"-epi-sulfhydryl 3"-N- substituted derivatives of formulae V (a and b)by treatment thereof with benzyl bromide and thence treatment of theintermediary salt thereby formed with hydrogen sulfide.

Another novel class of aminoglycoside intermediates of this inventionare members selected from the group consisting of2"-deoxy-3"-desamino-Z", 3"-epiminoaminoglycosides of structuralformulae Vlla and Vllb and cyclic ketals and acetals thereof:

H 5 a R SWC R I 6 R5 on R; Q l R' HOWW vII(

H R E SWVCWNH2 NHZ HO O VII(b) wherein R is a member selected from thegroup consisting of amino and hydroxy; R and R are each members selectedfrom the group consisting of hydrogen and hydroxy; R R and R are eachmembers selected from the group consisting of hydrogen and methyl; R isa member selected from the group consisting of hydroxy, amino andmethylamino; and R is a member selected from the group consisting ofhydrogen and hydroxymethyl.

Typical intermediates of formulae Vlla and Vllb are as follows:

methylepiminogentamicin C methylepiminogentamicin C a,

2 '-deoxy-3 '-desmethylamino-2 ,3 '-N- methylepiminogentamicin C2-deoxy-3 -desmethylamino-2 ",3 "-N- methylepiminosisomicin,

4,6'-O-iso-pr0pylidene-2 -deoxy-3'desmethylamino-2,3"-N-methylepiminogentamicin X and,

2 ,3 '-epiminotobramicin.

The intermediates of formulae VIIa and Vllb are prepared by removing thecarbobenzyloxy protecting groups from a2"-O-methanesulfonyl-per-N-carbobenzyloxyaminoglycoside by reduction.The resulting 2"- O-methanesulfonate ester then converts to a 2-deoxy- 3-desamino-2' ,3 '-epimino derivative spontaneously of when heated inrefluxing alkanol either alone or with an alkali metal salt of analkanol.

Other intermediates formed in the alternate process of this inventioninclude 2"-deoxy-2"-thiosubstituted derivatives and2"-deoxy-3"-desamino-2"-epi-amino- 3-epi-thiosubstituted aminoglycosidederivatives selected from the group consisting of compounds of followingformulae Vllla, Vlllb, IXa and lXb and cyclic ketals and acetalderivatives thereof:

e! NHR How -A VIII(a) R v- C NH2 H2 0 I NH2 NHC H3 VIII(b) H g R WMHZ Iam/M 6 NH2 2 mt r H2 I 2 NHZ RSI! W H a now) wherein R ',R ,R ,R ,R ,R,R and R are as defined for formulae Ia and lb, and A is a memberselected from the group consisting of hydrogen, lower alkyl, aralkyl,aryl and lower alkanoyl.

The aryl, aralkyl, and alkanoyl groups contemplated for A in aboveformulae VIII(a), VIII(b), IX(a) and IX(b) have preferably up to eightcarbon atoms including aryl radicals such as phenyl, tolyl and xylyl,aralkyl radicals such as benzyl, ethylphenyl and methyltolyl, andalkanoyl radicals such as acetyl and caprylyl.

The derivatives of formulae VIII(a), and VIII(b), IX(a) and IX(b) arederived from the corresponding intermediates of formulae Vll(a) andVII(b) by treatment thereof with a sulfur nucleophile as described inthe examples and in the description of the processes hereinbelow.Compounds of formulae IV(a) and IV(b) are per-N-alkanoyl derivatives ofcompounds of formulae VIII(a) and VIII(b) but wherein A is alkyl.

Typical intermediates of the above formulae include the following:

2"-deoxy-2"-sulfhydrylgentamicin C (compound of formula VIIl( a) whereinR and R are amino; R and R and R are hydrogen; R R and R are methyl; andA is hydrogen).

2 -deoxy-3 -desmethylamino-2 -epi-methylamino-3"-epi-sulfhydrylgentamicin C (compound of formula IX(a) wherein R and Rare amino; R R and R are hydrogen; R R and R are methyl; and A ishydrogen);

2"-deoxy-2"-phenylthiosisomicin (compound of formula VIII(b) wherein Ris hydrogen and A is phenyl); and

2 -deoxy-3 -desmethylamino-2 -epi-methylamino-3"-epi-acetylthiosisomicin (compound of formula IX(b) wherein R ishydrogen and A is acetyl).

General Description of the Process Aspects of the Invention llh areprepared by processes defined in the summary of this invention. Inbrief, in one process, an anti-bacterially active aminoglycoside havinga 2"-hydroxy function and having all primary and secondary amino groupsprotected and protectable primary and secondary hydroxyl groupsderivatized, upon treatment with a hydrocarbonsulfonyl halide in atertiary amine is converted to a 2"-O-hydrocarbonsulfonyl ester (e.g. toa 2-O-methanesulfonyl ester) which, in turn is converted to a2"-thio-2"-deoxyaminoglycoside derivative selected from the groupconsisting of a 2"-alkylthio- 2"-deoxy derivative, a2"-epi-sulfhydryl-2"-deoxy derivative, a 2"-epi-benzylthio-2 -deoxyderivative and a 2' '-epi-carboxymethylenethio-Z -deoxy derivative, thensaid 2"-thio-2"-deoxyaminoglycoside derivative following acid hydrolysisof any acetal or ketal which may be present, is idesulfurized followedby basic hydrolysis of any-N-alkanoyl protecting groups which may bepresent, whereby is obtained a 2 '-deoxyaminoglycoside of fomiulae laand lb having anti-bacterial activity.

In this process, the 2"-alkylthio-2"-deoxy species of the2"-thio-2"-deoxyaminoglycoside intermediates are prepared by treating a2"-O-hydrocarbonsulfonylaminoglycoside having N-alkanoyl protectinggroups with an alkali metal salt of an alkanethiol, (e.g. lithiumethanethiolate) whereby is obtained a 2"-alkylthio-2"-deoxyaminoglycoside having N-alkanoyl protecting groups.Alternatively, the 2"-epi-sulfhydryl- 2-deoxy species of the2"-thio-2"-deoxyaminoglycoside intermediates of this invention areprepared by treating a 2"-O-hydrocarbonsulfonylaminoglycoside havingN-thioalkanoyl, N-thiobenzoyl or N-alkylthiocarbamoyl protecting groupsin an aqueous medium at temperatures in the range of from about 25 toabout C followed by mild acid hydrolysis of any acetal or ketalfunctions which are present and thence treatment of the thereby formedper-N-substituted-Z"-epi sulfhydryl-2-deoxyderivative in a basichydrolytic medium whereby is formed a2"-epi-sulfhydryl-2"-deoxyaminoglycoside having free amino and hydroxylgroups. Alternatively, reaction of the aforementionedper-N-substituted-2 -epi-sulfhydryl-2 '-deoxyderivative with ahydrocarbon halide, e.g. benzyl bromide, or an a-halogeno alkanoic acid,e.g. a-bromoacetic acid, respectively, followed by treatment of theresulting S- substituted salt with hydrogen sulfide yields, e.g. the 2-epi-benzylthio-2 -deoxyand 2 -epi-carboxymethylenethio-2"-deoxyspeciesof the 2"-thio-2"- deoxyaminoglycoside intermediates of this invention,respectively, said species having the 3"-amino group protected by anN-alkanoyl, N-aroyl or an N-alkylcarbamoyl group.

tertlary amlne H0 in 6- $02M 0?;9 III This process of my invention isindicated schematically hereinbelow in Chart A wherein (with referenceto formulae Ia and lb and the disclosure immediately following) there isshown only the 3-amino sugar ring of the aminoglycosides of thisinvention, the Roman numeral below each partial formula referring to thestructural formula so identified hereinabove in the general descriptionof the compounds of this'invention, the substituent v designating theother two rings of the 10 aminoglycoside as disclosed hereinabove.

' .Acid Hydrolysis of Q-Protecting Groups R" CHART A The startingcompounds of my invention (designated as Compound A in Chart Ahereinabove) can be any aminoglycoside having a 2"-hydroxyl group whichexhibits antibacterial activity against gram positive and/or gramnegative organisms as determined by conventional in vitro techniquessuch as tube dilution tests, agar dilution tests, disc diffusion tests,and the like. An aminoglycoside which inhibits bacteria atconcentrations equal to or less than about 50 to 100 mcg./ml. isconsidered to be an antibacterial agent. These aminoglycosideantibacterial starting compounds can be antibiotics such as gentamicin Cor derivatives of antibiotics such as 3,4'-dideoxykanamycin B.

Typical starting aminoglycoside antibacterials are such as thegentamicins (including gentamicin A, gentamicin B, gentamicin B,,gentamicin C gentamicin C gentamicin C gentamicin C gentamicin X andmixtures thereof), sisomicin, verdamicin, Antibiotic JI-20-A, AntibioticJI-20-B, Antibiotic G-4l8, tobramycin and 3,4'-dideoxykanamycin B. Ofthe foregoing, preferred starting antibiotics are gentamicin Cgentamicin C gentamicin C gentamicin C sisomicin and verdamicin whichlead to the corresponding 2"-deoxy derivatives, preferred compounds ofthis invention as defined by formulae L, and 1 Most of theaforementioned aminoglycoside antibiotics are known. Of the gentamicins,the starting compound referred to herein as gentamicin X is also knownin the art as gentamicin X; the starting compounds referred to herein asgentamicin C and gentamicin C are stereoisomeric with each other aboutthe carbon at the 6-position (i.e. the 6-carbon atom) gentamicin C beinga 2-hydroxy derivative of formula L, hereinabove wherein R is methyl, Ris amino, and the stereochemistry at C-6'is R; gentamicin C being a2-hydroxy derivative of formula L, wherein R is methyl, R is amino, andthe stereochemistry at C-6 is S. The isolation, properties and planarconfiguration of gentamicin C2 is described in U.S. Pat. No. 3,651,042;while the isolation, properties and planar configuration of gentamicin Cas well as the stereoconfiguration about 06' of gentamicin C and C isdescribed in copending application of common assignee as that of theinstant application of Peter J. L. Daniels and J. A. Marquez, entitledNovel Antibiotic from Micromonospara, Ser. No. 269,914 filed July 7,1972, now abandoned.

Verdamicin, Antibiotic G-418, Antibiotic JI--A and Antibiotic JI-20-Bare all also described in copending U.S. applications of common assigneeas that of the instant application; verdamicin being described in U.S.application Ser. No. 208,907 filed Dec. 16, 1971 as acontinuation-in-part of U.S. Ser. No. 58,050 filed July 24, 1970, nowabandoned, of M. J. Weinstein, G. H. Wagman, and J. Marquez entitledAntibiotic and Process For Their Manufacture; Antibiotic G418 beingdescribed in application U.S. Ser. No. 196,707 filed Nov. 8, 1971 of M.J. Weinstein, G. H. Wagman, R. Testa and J. Marquez entitled AntibioticG-4l8 and Production Thereof; while Antibiotics JI-20- A and JI-20-B aredescribed in application U.S. Ser. No. 261,753 filed June 12, 1972 ofJan Ilavsky, Aris P. Bayan, William Charney and Hans Reimann entitledNew Antibiotic from Micromonospora Purpurea JI-ZO.

Prior to carrying out my process as outlined in Chart A, it is necessaryto protect functions in the aminoglycoside starting compound A whichwould be reactive to the reagents used therein, such as primary andsecondary amino groups and hydroxyl groups. In particular, it isnecessary to protect all primary and secondary amino functions by groupswhich can be easily removed without affecting the rest of the molecule.The choice of the amino protecting groups is also dependent upon theroute one wishes to take in converting starting compound A to the2-deoxyaminoglycosides(I) of my invention. If one carries out my processvia conversions A III IV I" I as designated in Chart A, the protectinggroups of choice are lower alkanoyl groups, preferably acetyl; whereas,when my process is to be carried out via the conversions indicated onChart A as A III V VI I, the protecting groups of choice arethioalkanoyl (preferably thioacetyl), thioaroyl (preferably thiobenzoyl)and lower alkylthiocarbamoyl (preferably methylthiocarbamoyl). The amineprotected derivatives are prepared according to methods known in the artas illustrated in the Preparations hereinbelow.

In order to minimize competing reactions in my process, primary hydroxylgroups and protectable neighboring hydroxyl groups in aminoglycosidestarting compounds are also preferably protected prior to car- -ryingout the conversions shown in Chart A, usually by a cyclic acetal orcyclical ketal of vicinal and neighboring hydroxyl groups or by an ether(preferably a triphenylmethyl ether, also called a trityl ether) of anyprimary hydroxyl groups. Thus, for example (with reference to Chart A),prior to the conversion of the starting compounds (A) to the2"-O-hydrocarbonsulfonate esters (III) and, after the primary andsecondary amino functions have been protected, vicinal hydroxyl groupssuch as those at the 3' and 4 positions in Antibiotics JI-20-A and JI-20-B and those at the 2', 3, and 4 positions in gentamicin B and B areconverted to a cyclic ketal (e.g. to a 3,4'-O-iso-propylidene) or to acyclic acetal (e.g. to a 3,4'-O-benzylidene) by reaction thereofaccording to methods known in sugar chemistry as illustrated in theProcedures hereinbelow. In the case of gentamicin B and B mixtures ofthe 3,4' and 2',3'-O-ylide'ne derivatives are formed, which mixtures canbe used, as is, in my process. Primary hydroxyl groups such as arepresent at O6 in gentamicin A and X or at C-6 in tobramycin and3,4-dideoxykanamycin B can be protected by conversion to thecorresponding trityl ether by reaction with triphenylmethyl chloride inpyridine or, together with a neighboring hydroxyl group, by conversionto a cyclic ketal or a cyclic acetal, e.g. to the 4,6-O-iso-propylidenederivatives of gentamicin A and of gentamicin X and to the 4,6-O-iso-propylidene derivatives of tobyramycin and 3',-4'-dideoxykanamycin B. Exemplary of other protectable, neighboringhydroxy groups is the grouping of secondary hydroxyl groups at C-3, C-4'and C-6 in Antibiotic G-4l8 which form a 4,6'-O-ylidene derivative whenreacted with dimethoxypropane or benzaldehyde, for example.

The O-protecting groups present in the starting aminoglycosides (A) ofthe process outlined in Chart A can be removed at any stage afterpreparation of the 2-hydrocarbonsulfonate ester derivative (III) by mildacid hydrolysis; however, when following reaction sequence III IV I I(in which sequence ketal or acetal O-protection groups are usuallyemployed) removal of the ketal or acetal functions is convenientlycarried out just prior to treatment of the 2"-thio-2- deoxy intermediate(IV) with Raney Nickel; whereas,

when following sequence III V VI I, removal of the O-protecting groupsis usually effected immediately after preparation of the sulfonate esterderivative (III) by subjecting any ketals or acetals to acid hydrolysis,while any trityl ether derivatives will cleave in the presence of acidduring the conversion in an aqueous medium of the hydrocarbonsulfonateester (III) to an episulfhydryl intermediate (V).

In the first step of my process, the 2"-hydroxy function in anaminoglycoside starting compound (A) is converted to the correspondinghydrocarbonsulfonate ester, i.e. .to a 2"-O-hydrocarbonsulfonylderivative (III), by treatment of said 2"-hydroxyaminoglycoside with anacid halide of a hydrocarbon-sulfonic acid in a tertiary amine (apreferred reagent mixture being methanesulfonyl chloride in pyridine).

Any hydrocarbonsulfonic acid halide having up to eight carbon atoms issuitable for use in this first step of my process, including the acidbromide and acid chloride derivatives of methanesulfonic acid,ethanesulfonic acid, benzenesulfonic acid and p-toluenesulfonic acid,methanesulfonic chloride being a reagent of choice.

Among the tertiary amines contemplated as suitable for use in theesterification step of my process are tertiary aliphatic and aromaticamines including cyclic amines such as trimethylamine, triethylamine,collidine, dimethylaminopyridine and, preferably, pyridine, which serveboth as solvent and basic agent.

A convenient method of carrying out a preferred species of thisesterification step of my process (i.e. that which utilizesmethanesulfonyl chloride in pyridine as the esterification medium)comprises preparing a solution of the aminoglycoside antibiotic havingall primary and secondary amino groups and vicinal hydroxyl groupsprotected, e.g. penta-N-acetylgentamicin C in dry pyridine to which isthen added an acid halide, e.g. methanesulfonyl chloride, in amounts offrom about I to 1.5 moles of acid halide per mole of aminoglycoside(usually about 1.1 moles of acid halide), and allowing this solution tostand at room temperature (about C) for a period of about I to 6 hours,usually 3 hours. Anhydrous alkanol, e.g. methanol, is then added todecompose any excess sulfonic acid halide and the2"-O-hydrocarbonsulfonyl derivative of formula II thereby prepared, e.g.2"-O-methanesulfonyl-penta-N- acetylgentamicin C is then convenientlyisolated and purified utilizing techniques known in the art such assolvent distillation, solvent extraction, precipitation,crystallization, chromatography and the like.

The 2 '-O-hydrocarbonsulfonyl-per-N-substituted aminoglycosides offormula III are key intermediates of this invention from whence,depending on the nature of the N-protecting groups in theaminoglycosides, different routes may be taken to obtain the novel2-deoxyaminoglycosides of formula I. When the amino protecting groupsare lower alkanoyl, preferably acetyl, the 2"-deoxyaminoglycosideproducts of formula I are conveniently derived from the 2-O-hydrocarbonsulfonyl derivatives (III) via route III IV- I I bytreatment thereof with an alkali metal thioalkanolate in a polar,non-hydrolytic medium followed by acid hydrolysis of any cyclic ketal oracetal functions present, thence, treatment of the resultingper-N-substituted- 2"-alkylthio-2"-deoxyaminoglycoside of fonnula IVwith Raney Nickel in an alkanol whereby is obtained aper-N-substituted-2"-deoxyaminoglycoside intermediate of formula I,which, upon alkaline hydrolysis utilizing known techniques, is convertedto a novel 2"- 28 deoxyaminoglycoside anti-bacterial agent of formula I,having free amino groups.

When converting a 2 -O-hydrocarbonsulfonylaminoglycoside of formula III,e.g. 2"-O- methanesuIfonyl-penta-N-acetylgentamicin C to thecorresponding 2"-alkylthio-2"-deoxy derivative of formula IV, e.g. to2"-ethylthio-2"-deoxy-penta-N-acetylgentamicin C the 2"-O-sulfonyl esterderivative is usually added to a solution comprising an anhydrous,polar, non-hydroxylic solvent containing about a molar excess of analkali metal alkanethiolate (e.g. lithium ethanethiolate) with stirring,under an atmosphere of an inert gas (e.g. nitrogen, argon, and the like)at low temperatures (usually 0 to 4C) followed by heating at elevatedtemperatures for several hours, e.g. in the range of to 150C for 2 to 6hours. The 2"- alkylthio-2"-deoxy derivatives of formula IV therebyformed, e.g. 2"-ethylthio-2"-deoxy-penta-N-acetylgentamicin C areconveniently isolated and purified utilizing chromatographic and solventextraction techniques.

Alkali metal salts of thioalkanolates which are most suitable for StepIII IV of my process are alkali metal salts of low molecular weight(e.g. potassium, sodium, lithium) of lower alkanethiols (e.g.methanethiol, ethanethiol, and propanethiol). A preferred salt for usein this step of our process is lithium ethanethiolate prepared byaddition of butyl lithium to ethanethiol in anhydrous dimethylformamide,for example. Other alkali metal salts which may be used are sodiumn-propanethiolate (derived from sodium hydride and n-propanethiol) andpotassium ethanethiolate (derived from potassium-hydride andethanethiol).

Solvents suitable for use in the step of converting a2"-O-hydrocarbonsulfonylaminoglycoside of formula III to thecorresponding 2-alkylthio-2-deoxy derivative of formula IV include anyanhydrous, polar, nonhydroxylic solvent, particularly amides such ashexamethylphosphoric triamide (HMPT or I-IMPA) and, preferably,dimethylformamide or dimethylacetamide.

The desulfurization step of my process as illustrated by conversion IVI" in Chart A hereinabove is conveniently carried out utilizing RaneyNickel. Usually, a 2"-alkylthio derivative of formula IV (e.g. 2"-ethylthio-2"-deoxy-penta-N-acetylgentamicin C is dissolved in a suitablesolvent (e.g. ethanol, water, or

aqueous alkanol) and stirred with an excess of Raney Nickel (e.g. about20 times the weight of aminoglycoside) at reflux temperature for severalhours (e.g. 3 to 6 hours). Isolation of the resulting 2-deoxy-per-N-alkanoyl derivative of formula I(e.g. 2-deoxy-penta- N-acetylgentamicinC is easily carried out by removing the Raney Nickel by filtrationfollowed by distillation of the solvent.

The anti-bacterially active 2"-deoxyaminoglycosides (I) are then easilyderived from the per-N-alkanoyl-2"- deoxy intermediates (I") by alkalinehydrolysis. For example, by adding a penta-N-alkanoyl derivative offormula I, e.g. 2"-deoxypenta-N-acetylgentamicin C to aqueous bariumhydroxide or to aqueous sodium hydroxide (e.g. to a 4 to 5 NormalSolution) and heating the resulting solution in a sealed tube(preferably lined with a substance impervious tostrong alkali) atelevated temperatures (usually about C) for long periods of time(usually for about 2 to 3 days). Isolation of the thereby formed novel2"-deoxyaminoglycoside (I) of this invention is then effected utilizingchromatographic techniques.

Referring to Chart A, an alternate method for carrying out my process isfollowed when the amino protecting groups are thio-derivatives such asthioalkanoyl (preferably thioacetyl), thioaroyl (preferably thiobenzoyl)or lower alkylthiocarbamoyl (preferably methylthiocarbamoyl) whereby a2"-O-hydrocarbonsulfonylaminoglycoside intermediate (III) is convertedto a 2-deoxyaminoglycoside antibacterial (I) via route III v VI I. I

By this route, a per-N-thio-substituted-2"-O-hydrocarbonsulfonylaminoglycoside (III) is converted to aper-N-substituted-2"-epi-sulfhydryl-2-deoxyaminoglycoside (V) by simplyheating the 2"-O- hydrocarbonsulfonylaminoglycoside in an aqueous mediumat temperatures in the range of 25 to 150C (usually about 100C) forperiods of from about 30 minutes to 2 hours until no further startingsulfonate ester is present in the reaction mixture as determined by thinlayer chromatography. The resultant per-N-substituted-2-epi-sulfhydryl-2 -deoxyaminoglycoside intermediate is then convenientlyisolated utilizing known techniques after any O-protecting groupspresent have been removed via mild acid hydrolysis.

Aqueous media suitable for use in the solvolysis step III V of myprocess may be any solvent which does not affect the aminoglycosideintermediate and which contains water. Such media include water alone,aqueous solutions of lower alkanols (e.g. aqueous methanol and aqueousethanol) and, preferably, aqueous dimethylformamide.

In this solvolysis step, the thioamide group at the 3 position, e.g.3"-N-thioacetyl, 3"N-thiobenzoyl or 3 N-(N-methylthiocarbamoyl), isconverted to the corresponding oxygen analog, e.g. to the 3"-N-acetyl, 3N-benzoyl or 3"-N-(N-methylcarbamoyl) groups, respectively, while theother thioamide groups in the aminoglycoside derivative V remainunchanged.

Usually, when carrying out solvolysis step II -+V, aper-N-thiosubstituted-2 -O-sulfonylaminoglycoside (III) (e.g.2"-O-methanesulfonyl-penta-N-thioacetylgentamicin C2"-O-methanesulfonyl-penta-N-thiobenzoylgentamicin C and2"-O-methanesulfonylpenta-N-(N-methylthiocarbamoyl) gentamicin C isheated in aqueous dimethylformamide (5 parts water to 95 parts DMF) atabout 80C for about an hour. Evaporation of the solvent in vacuo,followed by chromatography over silica gel using a2:1:l-chloroformmethanol-l5% ammonia system as eluant yields a2-episulfhydryl derivative (V), e.g. 2"-eip-sulfhydryl-2"- deoxy-3-N-acetyl-tetra-N-thioacetylgentamicin methylthiocarbamoyl) gentamicin Crespectively. After solvolysis of the 2"-O-sulfonate ester (III) andprior to purification of the 2-sulfhydryl derivative (V), andO-protecting groups (e.g. trityl ethers, ketals or acetals) present areconveniently removed by mild acid hydrolysis (e.g. dilute acid at roomtemperature). Alternatively, aminoglycoside starting compounds (A)having primary hydroxyl groups (e.g. gentamicin A, gentamicin Xtobramycin and 3,4'-dideoxykanamycin B) after protection of the aminogroups therein, may be converted to a 2-O-sulfonate ester intermediate(III) having the primary hydroxyl group also esterified (e.g. to6,2"-bis-O-sulfonyl derivatives of per-N- thioacetylgentamicin A and ofper-N-thioacetylgentamicin X or to 2",6"-bis-O-sulfonyl derivatives ofper-N-thioacetyltobramycin and of per-N-thioacetyl-3,4'-dideoxykanamycin B). Upon solvolysis of the thus formedpolysulfonate ester intermediates in aqueous dimethylformamidecontaining sodium acetate, the primary sulfonate ester will hydrolyzeand there is formed a 2"-eip-sulfhydryl intermediate (V) having free primary hydroxyl groups (e.g. 2"-eip-sulfhydryl-2"-deoxy-3"-N-acetyl-per-N-thioacetyl derivatives of gentamicin A,gentamicin X tobramycin and of 3,4- dideoxykanamycin B). I

The sulfur-containing N-protecting groups of intermediates Varedesirably removed prior to the desulfurization step of my process. Thismay be done directly (i.e. by step V VI in Chart A) via alkalinehydrolysis utilizing techniques similar to those used when hydrolyzingN-alkanoyl protecting groups (i.e. step I" I) described hereinabove.Thus, for example, a 2-episulfhydryl intermediate of formula V, e.g.2"-episulfhydryl-2"-deoxy-3-N-acetyl(or benzoyl or N'- methylcarbamoyl)-tetra-N-thioacetyl( or thiobenzoyl orN-methylthiocarbamoyl)-gentamicin C upon treatment with aqueoussodiumhydroxide (e. g. about 4 Normal) at elevated temperatures (e.g. C)in a sealed Teflon-lined tube for several days will yield a 2')t-'-epi-sulfyhydryl intermediate (VI) free of N-protecting groups, e.g.2"-eip-sulfnydryl-2"-deoxygentamicin C of formula VI wherein L ishydrogen, which, upon desulfurization in ethanol according to my processas described hereinabove with reference to step IV I yields a2-deoxyaminoglycoside of formula I having antibacterial activity, e.g.2"-deoxygentamicin C Optionally, the intermediate VI wherein L ishydrogen may be acylated to form an intermediate VI wherein L isacyl(e.g. acetyl) and having corresponding N-acyl groups(e.g. N-acetyl)which is then converted via the reaction sequence VI(L is acyl) I I asdescribed hereinbelow.

Alternatively, the sulfur-containing N-protecting groups of the2-epi-sulfhydryl-2"-deoxy intermediates of formula V are removed viareaction sequence V VI I" I by forming S-alkylated halide salts of eachof the N-thiocarbonyl derivatives followed by treatment thereof withhydrogen sulfide whereby is obtained a 2 -epi-sulfhydryl-2 '-deoxy-3-N-alkanoyl (or 3"-N-aroyl or 3 "-N-(N-alkylcarbamoyl derivative offormula VI) wherein L is the hydrocarbon (or other) radical of thehalide agent, which compound, upon desulfurization followed by alkalinehydrolysis according to my process, yields a 2"-deoxyam'inoglycoside offormula l. S-alkylated halide salts which are useful in this alternativedeblocking method of my process are preferably those formed with benzylbromide, although salts formed with other halides such as methyl iodideor a-bromoacetic acid may be used. More specifically, when carrying outconversions V VI I I of my process, a2-epi-sulfhydryl-2"-deoxy-per-N-substituted derivative of formula V,e.g. 2"-epi-su1fhydryl- 2"-deoxy-3"-N-acetyl(or thiobenzoyl orN-methylcarbamoyl)-tetra-N-thioacetyl(or thiobenzoyl or N-methylthiocarbamoyl)-gentamicin C is dissolved in a dry halogenatedhydrocarbon solvent (e. g. dry chloroform) to which is added an excessof a halide agent (e.g. a-bromoacetic acid, methyl iodide, or,preferably, benzyl bromide); and the solution is allowed to stand atroom temperature for several hours during which time the thereby formed2"-epi-benzylthio-per-N-(a-benzylthio)alkylidene-aminoglycosidequaternary halide salt precipitates and is easily isolated by filtrationand, without further purification, is suspended in anhydrous alkanol(e.g. anhydrous ethanol) and treated with hydrogen sulfide to obtain a2"-epi-benzylthio-3-N- alkanoyl (or aroyl orN'-methylcarbamoyl)-aminoglycoside (VI), e.g.2"-epi-benzylthio-3"-N-acetyl-(or benzoy] orN'-methylcarbamoyl)-gentamicin C Desulfurization of the foregoingintermediate VI (wherein L is benzyl) yields a 2"-deoxy-3-N-loweralkanoyl(or aroyl or N'-methylcarbamoyl)-aminoglycoside of formula I.Alkaline hydrolysis removes the amino protecting group at O3" to give a2"-deoxyaminoglycoside of formula I, e.g. 2"-deoxygentamicin C Inaddition to the process of my invention outlined in (X iscarbobenzyloxy) nuc @Desuliurizetion Chart A and discussed hereinabove,the novel 2"-deoxyaminoglycosides of formulae l (a and b) and ll (a andb) are prepared by another process as outlined in Chart B hereinabove.Only the EW-amino sugar ring of the aminoglycosides of this inventionare shown, the Roman numeral below each partial formula referring to thestructural formulae identifications disclosed in the general descriptionof the compounds of this invention, the substituent V designating theother two rings of the aminoglycosides as disclosed hereinabove.

MSO halide EeriIary aml' ne 9 spontaneously A alone or A plus alkalimetal in alkanol Q) I'L-Derivntization CGHSCHEBT (optiBTzal step) H(catalyst) Alkalinehycirolysis N-Dcrivatization; Desulfurization;@Removal of N-deriv- 3 ativcs; Separation of I and 1 II before or afterStep 3.

A=H, hydrocarbon, alkanoyl.

CHART B In brief, in alternateprocess B, an antibacterially activeaminoglycoside having a 2"-hydroxy function and a 3"-primary orsecondary amino function, and having all primary and secondary aminofunctions protected by N-carbobenzyloxy groups and having allprotectable primary and secondary hydroxy neighboring groups protectedby a cyclic ketal or acetal, is converted to aper-N-carbobenzyloxy-2"-O-hydrocarbonsulfonate ester (III), followed byremoval of the carbobenzyloxy groups usually by hydrogenation in thepresence of a catalyst or, when easily reduceable double bonds arepresent in the molecule such as the 4,5'-double bond in sisomicin andverdamicin, by cleavage with an alkali metal (e.g. lithium, sodium andpotassium) in liquid ammonia, using 2 gm. atoms of said alkali metal foreach carbobenzyloxy group present. The 2"-O-hydrocarbonsulfonate esterhaving free amino groups (III') thereby formed either spontaneously ringcloses in situ to form a 2"-deoxy-3-desamino-2",3"-epiminoaminoglycosideintermediate (VII), or the conversion is effected by heating the2"-O-hydrocarbonsulfonate ester (III) in a lower alkanol (e.g. methanol)either alone or together with an equivalent molar quantity of an alkalimetal salt of said alkanol (e.g. sodium methylate) at temperatures inthe range of from about 25 to about 100C. The epimino (or methylepimino)intermediate (VII) thereby formed is then treated with hydrogen in thepresence of a catalyst (e.g. palladium on charcoal) followed by acidhydrolysis of any ketal or acetal functions which may be present wherebyis formed a product mixture comprising 2"-deoxyaminoglycosides offormula I and 2"-deoxy3"-desmethyalmino(or desamino )-2-epi-methylamino( or epiamino)-aminoglycosides of formula II which areseparable via chromatographic techniques.

Alternatively, prior to reduction, the epimino intermediate (VII)wherein R is methyl is N-derivatized (e.g. to a tetra-N-acetyloptionally followed by treatment with an organic halide (e.g. benzylbromide) to form a quaternary salt, e.g. a 2"-deoxy-3"-desmethylamino-2',3 N benzyl-N-methyl )-epiminoaminoglycoside quaternary bromide salt.Hydrogenation of the N-derivatized intermediate in the presence of acatalyst (e.g. Raney Nickel at high pressures and temperature or,palladium on charcoal when a quaternary salt has been prepared) followedby removal of the N- protecting groups via alkaline hydrolysis yieldsthe product mixture of compounds I and II. Alternatively, the epimino(or methylepimino) intermediate (VII) wherein R is hydrogen or methyl istreated with a sulfur nucleophile (e. g. sodium thiophenoxide) to obtaina mixture comprising a 2"-deoxy-2"-hydrocarbonthioaminoglycosideintermediate (VIII) and a 2"-deoxy- 3 -desamino (or desmethylamino )-2'-epi-amino-( or 2"-epi-N-methylamino)-aminoglycoside intermediate (IX)which upon desulfurization followed by acid hydrolysis of any ketal oracetal functions which may be present produces a product mixture of thenovel, antibacterially active aminoglycosides (I and II) of my inventionseparable via chromatographic techniques.

Alternatively, and in some cases preferably, desulfurization of theintermediates of formulae VIII and IX may be accomplished by formationof the N-protected derivatives (e.g. the per-N-acetyl derivatives),followed by desulfurization and removal of the N-protecting groups (e.g.using sodium or barium hydroxide in water according to knownprocedures). Separation OH and II is optionally carried out before orafter removal of the N-protecting groups.

The process of Chart B is also, and usually preferably, carried outaccording to procedures described in co-pending application Ser. No.299,983 filed concomitantly herewith now US. Pat. No. 3,868,360, of JayWeinstein and Peter J. L. Daniels for Process for Preparing2-Deoxy-3"-Desamino-2",3"-Epiminoaminoglycoside Derivatives, whereby theprimary and secondary amino functions in the aminoglycoside startingcompound are protected by Schiff base oxazolidine condensation productswith aldehydes (preferably N- benzylidene and N, O-benzylidenederivatives) which, after preparation of the 2"-hydrocarbonsulfonateester, are conveniently removed by treatment with dilute aqueous acid.The use of Schiff base-oxazolidine N- protecting groups represents animprovement of my process as outlined in Chart B in that the N-Schiffbase and N,O-oxazolidine groups are usually easier to prepare and toremove than are the N-carbobenzyloxy protecting groups of my process,and their use usually results in higher yields of the2"-deoxy-3"-desamino (or desmethylamino)-2 ',3 '-epimino (or N-methylepimino)aminoglycoside key intermediate of the process of Chart B.The processes shown in Charts A and B are illustrated in detailhereinbelow in the examples which should not be construed as limitingthe invention in spirit or in scope.

PREPARATION OF STARTING INTERMEDIATES PREPARATION l Per-N-loweralkanoylaminoglycosides A. l,3,2,6',3"-Penta-N-acetylgentamicin CDissolve 1.0 g. of gentamicin C, in 10 ml. of ethanol and add 3.0 ml. ofacetic anhydride with cooling and stirring. Allow the reaction mixtureto stand at room temperature for 5 hours, then add the solutiondropwise, with vigorous stirring, to 250 ml. of dry ether. Filter offthe resultant white precipitate, wash the precipitate with dry ether,and dry in vacuo at 50C to give 1 ,3 ,2',6,3 '-penta-N-acetylgentamicinC dihydrate; m.p. 360C (decomp.); [a] +l57 (0.3, water). B. In a mannersimilar to that described in Preparation 1A, treat each of the followingaminoglycoside antibiotics with acetic anhydride in methanol:

gentamicin C gentamicin C gentamicin C sisomicin,

verdamicin,

tobramycin,

3 ',4-dideoxykanamycin B,

antibiotic JI-20-A,

antibiotic JI-20-B,

gentamicin B,

gentamicin B antibiotic 6-41 8,

gentamicin A, and

gentamicin X Isolate and purify the resultant products in a mannersimilar to that described in Preparation 1A to give, respectively: I

l,3,2,6,3"-penta-N-acetylgentamicin C dihydrate, m.p. 36C (dec.), [a]+l46 (water),

1 ,3 ,2,6 ',3 "-penta-N-acetylgentamicin C dihydrate,

m.p. 360C (dec.), [a], +l60 (water), l,3,2',6,3"-pentaN-acetylgentamicin C 1,3 ,2,6 ',3 -penta-N-acetylsisomicin,

1,3 ,2 ',6 ',3 '-penta-N-acetylverdamicin dihydrate, [a],, +l47 (water),

"35 1,3,2", ,3 -penta-N-acetyltobramycin, 1 2,3-penta-N-acetyl-3,4-dideoxykanamycin l 32',6,3"-penta-N-acetyl-antibiotic Jl-20-A,l,3,2",6,3-penta-N-acetyl-antibiotic Jl-ZO-B,1,3,6',3f-tetra-N-acetylgentamicin B tetrahydrate,

[111 +1-l9 (water), 1,3,6,3 "-tetra-N-acetylgentamicin [02],, +l34-(water),

l,3,2,3 '-tetra-N-acetyl-antibiotic 6-4 1 8 monohydrate {04 +150?(water),

1,3,2',3 "-tetra-N-acetylgentamicin A, and

l,3,2,3 "-tetra-N-acetlygentamicin X C. In the procedure described inPreparation 1A, by substituting other alkanoic acid anhydrides foracetic anhydride, e.g. propionic anhydride, valeric anhydride, andcaprylic anhydride, there is obtained the corresponding penta-N-loweralkanoyl derivative, e.g.

l,3,2,6,3"-penta-N-propionylgentamicin C,,

l,3,2',6',3"penta-N-valerylgentamicin C andl,3,2,6,3"-penta-N-caprylylgentamicin C In similar fashion, there isobtained the penta-N-propiony|-, the penta-N-valeryl-, and thepenta-N-caprylylderivatives of the aminoglycoside starting compoundslisted in Preparation 1 B.

B, trihydrate,

PREPARATION 2 Per-N-lower thioalkanoylaminoglycosides and per-N-thioaroylaminoglycosides A. 1,3,2',6',3"-Penta-N-'1"hioacetylgentamicinC Add 1.0 g. of gentamicin C to a solution of thioacetylthioglycollicacid (1.65 g., 5.1 equiv.) in aqueous l N-sodiuni hydroxide solution(11.0 ml., 5.0 equiv.). Allow the solution to stand at 2C in therefrigerator for 10 days, then decant the aqueous solution from'theresultant dark oil which has separated; dissolve the oil in 10 ml. ofethanol and add dropwise into 200 ml. of ether. Isolate by filtrationthe reasultant solid precipitate comprising1,3,2',6,3"-penta-N-thioacetylgentamicin C yield 1.44 g.

Purify by chrornatographing over silica gel (50 g.),

eluting with chloroform-methanol-l5% ammonium hydroxide (211:1), combinethe like fractions as determined by thin layer chromatography, anddistill the combined eluates in vacuo to a residue comprising1,3,2',6,3"-penta-N-thioacetylgentamicin C B. In a manner similar tothat described in Preparation 2A, treat each of the followingaminoglycoside antibiotics with thioacetylthioglycollic acid inv aqueoussodium hydroxide:

gentamicin C gentamicin C gentamicin C sisomicin,

verdamicin,

antibiotic JI-ZO-A,

antibiotic JI--B,

gentamicin B,

gentamicin B antibiotic G-4l8,

gentamicin A,

gentamicin X tobramycin, and

3,4-dideoxykanamycin B.

Isolate and purify the resultant products in a manner similar to thatdescribed in Preparation 2A to give, respectively:

1,3,2,6',3 "-penta-N-thioacetylgentamicin C 1,3,2,6,3"-penta-N-thioacetylgentamicin C 36 13,2,6,3"-penta-N-thioacetylgentamicin C 13,2',6,3"-penta-N-thioacetylsisomicin, 1 32',6,3"-penta-N-thioacetylverdamicin, 13,2,6'3"-penta-N-thioacetyl-antibiotic JI-ZO-A, l,3,2',6,3"-penta-N-thioacetyl-antibiotic JI-ZO-B,l,3,6,3"-tetra-N-thioacetylgentamicin B, 1 3 6 l 3 2 l 3 2 l 3 l,3"-tetra-N-thioacetylgentamicin B ,3 -tetra-N-thioacetyl-antibiotic6-41 8, ,3"-tetra-N-thioacetylgentamicin in A,,2,3"-tetra-N-thioacetylgentamicin X ,3,2',6,3"-penta-N-thioacetyltobramycin, and 1,3 ,2 ,6 ,3 '-penta-N-thioacetyl-3,4 -dideoxykanamycin B. C. In the procedure of Preparation 2A, bysubstituting for thioacetylthioglycollic acid other lowerthioacylthio-glycollic acids, e.g. thiopropionylthioglycollic acid,thio-caprylylthioglycollic acid, and thiobenzoylthioglycollic acid,there is prepared the corresponding per-N-thioacylgentamicin C e.g.l,3,2,6',3"-penta- N-thiopropionylgentamicin C 1,3,2,6',3"-penta-N-thiocaprylylgentamicin C and 1,3,2,6,3"-penta-N- thiobenzoylgentamicin Crespectively. D. In procedure of Preparation 28, by substitutingthiobenzoylthioglycollic acid for thioacetylthioglycollic acid there isprepared the corresponding per-N-thiobenzoylaminoglycoside.

PREPARATION 3 Per-N-( N -methylthiocarbamoyl )aminoglycosides A.1,3,2,6,3"-Penta-N-(N-methylthiocarbamoyl)- gentamicin C To a solutionof 2.0 g. of gentamicin C in 40 ml. of methanol, add 3.2 g. of methylisothiocyanate (10.2

equiv.). Allow the reaction mixture to stand at room temperature for 3days. Evaporate the solvent in vacuo to a residue comprising1,3,2',6,3-penta-N-(N- methylthiocarbamoyl)gentamicin C as an amorphousyellow solid; yield 3.1 g.

Purify by dissolving the amorphous solid in a minimum amount of methanoland adding the methanol solution to a large volume of ether. Separate byfiltration the resultant cream-colored solid which can be used withoutfurther purification in the process of this invention as described inthe Examples. To further purify, if desired, chromatograph over silicagel, eluting with 2: 1 :1 chloroform-methanol-l5% ammonium hydroxide,combine the like fractions as determined by thin layer chromatographyand evaporate to a residue comprising 1 ,3,2,6,3 -penta-N-( N'-methylthiocarbamoyl)gentamacin C as the hydrate; [a],, +lO3.O

(methanol). B. In a manner similar to that described in Preparation 3A,treat each of the following aminoglycoside antibiotics with methylisothiocyanate in methanol:

gentamicin C gentamicin C gentamicin C sisomicin,

verdamicin,

antibiotic JI-20-A,

antibiotic JI-20-B,

gentamicin B,

gentamicin B antibiotic 6-41 8,

gentamicin A,

gentamicin X tobramycin, and

3,4-dideoxykan'amycin B.

Isolate and purify the resultant products in a manner 37 similar to thatdescribed in Preparation 3A to give, respectively:

l,3,2',6,3"-penta-N-(N'-methylthiocarbamoyl)gen tamicin Cl,3,2,6,3"-penta-N-(N-methylthiocarbamoyl)gentamicin Cl,3,2,6',3"-penta-N-(N'-methylthiocarbamoyl)gentamicin C l,3,2',6',3'-penta-N-(N methylthiocarbamoyl)- sisomicin,

1,3,2 ,6 ,3 -pentaN-(N-methylthiocarbamoyl)verdamicin,

1,3,2,6 ,3 -penta-N-(N'-methylthiocarbamoylantibiotic JI-20-A,

l ,3,2,6,3"-penta-N-(N'-methylthiocarbamoyl)- antibiotic JI-ZO-B,

l ,3 ,6',3 "-tetra-N-( N -methylthiocarbamoyl )gentamicin, B,

1 ,3 ,6 ,3 -tetra-N-( N -methylthiocarbamoyl )gentamicin B 1,3,2,3-tetra-N-(N'-methylthiocarbamoyl )-antibiotic G-4l8,

1,3,2 ,3 -tetra-N-( N '-methy1thiocarbamoyl)gentamicin A,

1 ,3 ,2 ,3 '-tetra-N-( N'-methylthiocarbamoyl )gentamicin X 1 ,3 ,2 ,6,3'-penta-N-( N -methylthiocarbamoyl )totramycin, and

l ,3 ,2',6,3 -penta-N-(N '-methylthiocarbamoyl)-3 4-dideoxykanamycin B.

PREPARATION 4 O-Iso-propylidene-per-N-1ower thioalkanoylaminoglycosidesand O-Iso-propylidene-per-N-(N'-methylthiocarbamoyl)aminoglycosides A. 3',4-O-Iso-propylidene-1,3 ,2',6,3 -penta-N-thioacetylantibiotic JI-20-ATo a solution of 5.0 g. of 1,3,2,6,3"-penta-N-thioacetyl-antibioticJI-20-A in 25 ml. of anhydrous dimethylformamide, add 5 ml. of2,2-dimethoxypropane and 300 mg. of dry p-toluene-sulfonic acid, andheat in a sealed flask at 1 C for 4 hours. Cool the solution and thentreat the cooled solution with 6 ml. of Amberlite IR-401S resin in thehydroxide form. Filter off the resin and evaporate the filtrate in vacuoto a residue comprising 3,4'-O-iso-propylidene- 1 ,3,2',6',3-penta-N-thioacetyl-antibiotic JI--A which can be used without furtherpurification as an intermediate in my process as set forth hereinbelowin the Examples.

An analytical sample is prepared by chromatographing the foregoingresidue over silica gel, eluting with chloroform-methanol-l5% ammoniumhydroxide (2:1: 1 combining the like fractions as determined by thinlayer chromatography, and distilling the combined fractions in vacuo toa residue comprising 3',4'-O-isopropylidene- 1 ,3,2,6,3"-penta-N-thioacetyl-antibiotic JI-20-A. B. In a manner similar to thatdescribed in Preparation 4A, treat each of the followingper-N-thioacetylaminoglycosides in dimethylformamide with2,2-dimethoxypropane and dry p-toluene-sulfonic acid in a sealed flaskat 110C:

1,3,2,6,3 "-penta-N-thioacetyl-antibiotic J I-20-B,

l,3,6,3"-tetra-N-thioacetylgentamicin B,

1,3,6',3 "-tetra-N-thioacetylgentamicin B 1 ,3,2,3"-tetra-N-thioacetyl-antibiotic G-4 l 8,

1 ,3,2,3 -tetra-N-thioac etylgentamicin A,

l ,3,2,3 '-tetra-N-thioacetylgentamicin X 1,3,2 ,6,3-penta-N-thioacetyltobramycin, and

38 mycin B.

Isolate and purify the resultant products in a manner similar to thatdescribed hereinabove to obtain, respectively:

oacetylantibiotic JI-20-B,

a mixture comprising 2',3-O-iso-propylidene-1,3,6,3"-tetra-Nthioacetylgentamicin B and 3',- 4-Oisopropylidene-l ,3,6 ,3 -tetra-N-thioacetylgentamicin B,

a mixture comprising2',3-O-iso-propylidenel,3,6',3'f-tetra-N-thioacetylgentamicin B and 3',-4'-O-is0-propylidene- 1 ,3 ,6 ,3 -tetra-N-thioacetylgentamicin B4,6'-O-iso-propylidene- 1,3 ,2 ,3 '-tetra-N-thioacetylantibiotic 6-41 8,

4,6-O-iso-propylidenel ,3,2,3 "-tetra-N-thioacetylgentamicin A,

4,6'-O-iso-propylidene- 1 ,3 ,2 ,3 -tetra-N-thioacetylgentamicin X 4 ,6'-Oiso-propylidene- 1 ,3,2 ,6,3 -penta-N-thioacetyltobramycin, and

4",6-O-iso-propylidene-1,3,2 ,6,3 -penta-N-thioacetyl-3,4'-dideoxykanamycin B.

The foregoing products and product mixtures can be used without furtherpurification as intermediates in the process described hereinbelow inthe Examples. C. In the procedures of Preparations 4A and 48, bysubstituting for the per-N-thioacetylaminoglycoside starting compoundsnamed therein, other per-N-lower thioalkanoylaminoglycosides, such as1,3,2',6,3-penta-N-thiopropionyl-antibiotic .II-ZO-A, there is obtainedthe corresponding O-iso-propylidene derivative, e.g. 3',4'-O-iso-propylidene-l ,3,2 ,6 ,3 '-penta-N-thiopropionylantibioticJI-20-A.

D. O-Iso-propylidene-per-N-(N -methylthiocarbamoyl- )aminoglycosides Ina manner similar to that described in Preparations 4A and 4B, treat eachof the following per-N-(N- methylthiocarbamoyl)aminoglycosides indimethylformamide with 2,2-dimethoxypropane and dry p-toluenesulfonicacid in a sealed flask at C:

1 ,3 ,2,6 ,3 '-penta-N-(N-methylthiocarbamoyl)- antibiotic JI-20- A,

1 ,3 ,2 ,6 ,3 -penta-N-(N'-methylthiocarbamoyl antibiotic JI-'20-B,

1 ,3 ,6 ,3 -tetra-N-( N -methylthiocarbamoyl )gentamicin B,

1 ,3,6,3 "-tetra-N-(N-methylthiocarbamoyl)gentamicin B 1 ,3 ,2 ,3-tetra-N-(N' -methylthiocarbamoyl )-antibiotic G418,

1,3,2 ,3 "-tetra-N-(N-methylthiocarbamoyl)gentamicin A, and

1 ,3 ,2 ,3 -tetra-N-( N -methylthiocarbamoyl gentamicin X Isolate andpurify the resultant products in a manner similar to that described inPreparations 4A and 4B to obtain, respectively:

methylthiocarbamoyl)-antibiotic .lI-20-A,

3 ',4-O-iso-propylidene- 1 ,3,2,6,3 '-penta-N-(N'-methylthiocarbamoyl)-antibiotic JI-20-B,

a mixture comprising 2,3-O-iso-propylidene- 1 ,3 ,6 ,3 -tetra-N-( N-methylthiocarbamoyl)gentamicin B and 3',4-O-isopropylidene-l ,3,6,3-tetra-N-(Nmethylthiocarbamoyl)gentamicin B,

a mixture comprising 2,3-O-iso-propylidene- 1,3 ,6 ,3 -tetra-N-(N-methylthiocarbamoyl )gentamicin B, and 3,4'-O iso-propylidene-l,3,6',3

1. A COMPOUND SELECTED FROM THE GROUP CONSISTING OF A2"-DEOXYAMINOGLYCOSIDE SELECTED FROM THE GROUP CONSISTING OF2"-DEOXYGENTAMICIN A, 2"-DEOXYGENTAMICIN B, 2"-DEOXYGENTAMICIN B1,2-DEOXYGENTAMICIN C1, 2"-DEOXYGENTAMICIN C1A, 2"-DEOXYGENTAMICIN C2,2"-DEOXYGENTAMICIN C2A, 2"DEOXYGENTAMICIN X2, 2"-DEOXYSISONICIN,2"-DEOXYVERDAMICIN, 2"-DEOXY-ANTIOBITIC JI-20-A, 2"-DEOXY-ANTIBIOTICJI-20B, 2"-DEOXY-ANTIOBITIC G-418, 2"-DEOXYTOBRAMYCIN AND3'',4'',2"-TRIDEOXYKANAMYCIN B; THE 3"-DESMETHYLAMINO-2"EPI-METHYLAMINO-OR 3"-DESAMINO-2"-EPI-AMINO DERIVATIVES THEREOF; MIXTURES OF SAID2"-DEOXYAMINOGLYCOSIDE WITH THE 3"-DESMETHYLAMINO2"-EPI-METHLAMINOANALOG THEREOF OR WITH THE 3-DESAMINO-2"-EPI:AMINO ANALOG THEREOF; ANDTHE NON-TPXIC PHARMACEUTICALLY ACCEPTABLE ACID ADDITION SALTS OF THEFOREGOING.
 2. A 2''''-deoxyaminoglycoside of claim
 1. 3. A2''''-deoxyaminoglycoside of claim 1 which is 2''''-deoxysisomicin.
 4. A2''''-deoxyaminoglycoside of claim 1 which is 2''''-deoxyverdamicin. 5.A 2''''-deoxyaminoglycoside of claim 1 which is 2''''-deoxygentamicinC1.
 6. A 2''''-deoxyaminoglycoside of claim 1 which is2''''-deoxygentamicin C1a.
 7. A 2''''-deoxyaminoglycoside of claim 1which is a 2''''-deoxygentamicin C2.
 8. A 2''''-deoxyaminoglycoside ofclaim 1 Which is 2''''-deoxygentamicin C2a.
 9. A3''''-desmethylamino-2''''-epi-methylamino analog of a2''''-deoxyaminoglycoside of claim 1 which is2''''-deoxy-3''''-desmethylamino-2''''-epi-methylaminogentamicin C2. 10.A per-N-lower alkanoyl-derivative of a 2''''-deoxyaminoglycoside ofclaim
 1. 11. A compound according to claim 10 wherein the per-N-alkanoylderivative is a per-N-acetyl derivative and wherein said2''''-deoxyaminoglycoside is 2''''-deoxygentamicin C2, said compoundbeing per-N-acetyl-2''''-deoxygentamicin C2.
 12. A compound selectedfrom the group consisting of a 2''''-O-hydrocarbonsulfonyl derivative ofthe following structural formulae I and II:
 13. A compound according toclaim 12 wherein R3'''' is methyl and R5'''' is hydrogen.
 14. A compoundaccording to claim 12, formula I, wherein M is methyl, W2'' is -NHX,R3'', R4'' and R5'''' are hydrogen, R5'', R3'''' and R4'''' are methyland W6'' is
 15. A compound according to claim 12, wherein M is methyl;W2'' and W6'' are -NHX; R3'', R4'', R5'' and R5'''' are hydrogen; andR3'''' and R4'''' are methyl; said compound beingper-N-X-2''''-O-methanesulfonylgentamicin C1a wherein X is a memberselected from the group consisting of lower alkanoyl and carbobenzyloxy.16. A compound according to claim 12, formula I, wherein M is methyl,W2'' and W6'' are -NHX; R3'', R4'' and R5'''' are hydrogen; R5'', R3''''and R4'''' are methyl; the stereochemistry at C6'' being R; saidcompound being per-N-X-2''''-O-methanesulfonylgentamicin C2 wherein X isa member selected from the group consisting of lower alkanoyl andcarbobenzyloxy.
 17. A compound according to claim 12, formula I, whereinM is methyl; W2'' and W6'' are -NHX; R3'', R4'' and R5'''' are hydrogen;R5'', R3'''' and R4'''' are methyl; the stereochemistry at C6'' being S,said compound being Per-N-X-2''''-O-methanesulfonylgentamicin C2awherein X is a member selected from the group consisting of loweralkanoyl and carbobenzyloxy.
 18. A compound according to claim 12,formula II, wherein M is methyl and R5'' is hydrogen, said compoundbeing per-N-X-2''''-O-methanesulfonylsisomicin wherein X is a memberselected from the group consisting of lower alkanoyl and carbobenzyloxy.19. A compound according to claim 12, formula II, wherein M is methyland R5'' is methyl, said compound beingper-N-X-2''''-O-methanesulfonylverdamicin wherein X is a member selectedfrom the group consisting of lower alkanoyl and carbobenzyloxy.
 20. Acompound selected from the group consisting of a2''''-deoxy-2''''-sulfhydryl-aminoglycoside derivative of followingformulae I and II:
 21. A compound according to claim 20, Formula I,wherein A is ethyl, Y is acetyl, T2'' and T6'' are each acetamido; R3'',R4'', R5 '' and R5'''' are hydrogen; and R3'''' and R4'''' are eachmethyl; said compound being2''''-deoxy-2''''-ethylthio-1,3,2'',6'',3''''-penta-N-acetylgentamicinC1a.
 22. A compound selected from the group consisting of a2''''-deoxy-3''''-desamino-2'''',3''''-epimino-aminoglycoside offollowing formulae I and II:
 23. A compound according to claim 22,formula I, wherein R2'' is amino; R3'', R4'' and R5'''' are hydrogen:R5'', R3'''' and R4'''' are methyl; and R6'' is methylamino; saidcompound being2''''-deoxy-3''''-desmethylamino-2'''',3''''-N-methylepimino-gentamicinC1.
 24. A compound according to claim 22, formula I, wherein R2'' andR6'' are amino; R3'', R4'', R5'' and R5'''' are hydrogen; R3'''' andR4'''' are methyl; said compound being2''''-deoxy-3''''-desmethylamino-2'''',3''''-N-methylepimino-gentamicinC1a.
 25. A compound according to claim 22, formula I, wherein R2'' andR6'' are amino; R3'', R4'' and R5'''' are hydrogen; and R5'', R3'''' andR4'''' are methyl, the configuration at C6'' being R; said compoundbeing2''''-deoxy-3''''-desmethylamino-2'''',3''''-N-methylepiminogentamicinC2.
 26. A compound according to claim 22, formula I, wherein R2'' andR6'' are amino; R3'', R4'' and R5'''' are hydrogen; and R5'', R3'''' andR4'''' are methyl, the configuration at C6'' being S, said compoundbeing2''''-deoxy-3''''-desmethylamino-2'''',3''''-N-methylepiminogentamicinC2a.
 27. A compound according to claim 22, formula II, wherein R5'' ismethyl, said compound being2''''-deoxy-3''''-desmethylamino-2'''',3''''-N-methyl-epiminoverdamicin.28. A compound according to claim 22, formula II, wherein R5'' ishydrogen, said compound being 2''''-deoxy-3''''-desmethylamino-2'''',3''''-N-methylepiminosisomicin.
 29. A compound selected from the groupconsisting of a2''''-deoxy-3''''-desamino-2''''-epi-amino-3''''-epi-sulfhydrylaminoglycosidederivative of following formulae I and II:
 30. The process for preparinga 2''''-deoxy 4,6-di-(aminoglycosyl)-2-deoxystreptamine which comprisestreating an antibacterially active4,6-di-(aminoglycosyl)-2-deoxystreptamine having a 2''''-hydroxyfunction, the primary and secondary amino groups of which are protectedby a lower alkanoyl, and protectable primary and secondary hydroxylgroups of which are converted to an O-protecting function selected fromthe group consisting of a triphenylmethyl ether of a primary hydroxylgroup and a cyclic ketal or acetal of protectable neighboring hydroxylgroups; with a hydrocarbonsulfonyl halide having up to eight carbonatoms in a tertiary amine whereby is formed a2''''-O-hydrocarbonsulfonylaminoglycoside intermediate; converting said2''''-O-hydrocarbonsulfonylaminoglycoside intermediate to a2''''-thio-2''''-deoxyaminoglycoside intermediate by treating aper-N-lower alkanoyl-2''''-O-hydrocarbonsulfonylaminoglycoside with analkali metal salt of a lower alkylthiol in an anhydrous, polar,non-hydroxylic solvent, optionally followed by acid hydrolysis of anyO-protecting functions present, whereby the 2''''-thio-2''''-deoxyintermediate formed is a 2''''-lower alkylthio-2''''-deoxy-per-N-loweralkanoylaminoglycoside; treating said2''''-thio-2''''-deoxyaminoglycoside intermediate with a reductivedesulfurization agent selected from the group consisting of Raney Nickeland aluminum amalgam, followed by alkaline hydrolysis of any aminoprotecting groups, whereby is obtained a 2''''-deoxyaminoglycoside. 31.The process according to claim 30 wherein said antibacterially active4,6-di-(aminoglycOsyl)-2-deoxystreptamine having a 2''''-hydroxyfunction is a member selected from the group consisting of sisomicin,verdamicin, a gentamicin selected from the group consisting ofgentamicin A, gentamicin B, gentamicin B1, gentamicin C1, gentamicinC1a, gentamicin C2, gentamicin C2a, gentamicin X2 and mixtures thereof,tobramycin, 3'',4''-dideoxykanamycin B, Antibiotic JI-20-A, AntibioticJI-20-B and Antibiotic G-418, whereby is obtained the corresponding2''''-deoxyaminoglycoside antibiotic derivative selected from the groupconsisting of: 2''''-deoxysisomicin, 2''''-deoxyverdamicin, a2''''-deoxygentamicin selected from the group consisting of2''''-deoxygentamicin A, 2''''-deoxygentamicin B, 2''''-deoxygentamicinB1, 2''''-deoxygentamicin C1, 2''''-deoxygentamicin C1a,2''''-deoxygentamicin C2, 2''''-deoxygentamicin C2a, gentamicin X2 andmixtures thereof, 2''''-deoxytobramycin, 3'',4'',2''''-trideoxykanamycinB, 2''''-deoxy-Antibiotic JI-20-A, 2''''-deoxy-Antibiotic JI-20-B, and2''''-deoxy-Antibiotic-G-418.
 32. The process according to claim 30wherein the primary and secondary amino groups are protected by acetyl;wherein said hydrocarbonsulfonyl halide in a tertiary amine ismethanesulfonyl chloride in pyridine; wherein said2''''-thio-2''''-deoxyaminoglycoside intermediate is2''''-ethylthio-2''''-deoxy-per-N-acetylaminoglycoside prepared bytreating the correspondingper-N-acetyl-2''''-O-methanesulfonylaminoglycoside with the lithium saltof ethanethiol in anhydrous dimethylformamide.
 33. The process forpreparing a 2''''-deoxy-4,6-di-(aminoglycosyl)-2-deoxystreptamine whichcomprises treating an antibacterially active4,6-di-(aminoglycosyl)-2-deoxystreptamine having a 2''''-hydroxyfunction and a 3''''-primary or secondary amino function, the primaryand secondary amino groups of which are protected by a carbobenzyloxygroup, and protectable neighboring primary and secondary hydroxyl groupsof which are converted to a cyclic ketal or cyclic acetal function, witha hydrocarbonsulfonyl halide having up to eight carbon atoms in atertiary amine; removing the carbobenzyloxy groups from the2''''-O-hydrocarbonsulfonyl-per-N-carbobenzyloxyaminoglycoside therebyformed by treatment with hydrogen in the presence of a catalyst, or bycleavage with an alkali metal in liquid ammonia; converting theresulting 2''''-O-hydrocarbonsulfonylaminoglycoside to the corresponding2''''-deoxy-3''''-desamino-2'''',3''''-epimino-aminoglycosideintermediate by spontaneous transformation or by heating in a loweralkanol either alone or together with an alkali metal salt of saidalkanol, at temperatures in the range of from about 25* to about 100*C;cleaving the2''''-deoxy-3''''-desamino-2'''',3''''-epiminoaminoglycoside therebyformed by (1) treatment with hydrogen in the presence of a catalyst,followed by acid hydrolysis of any acetal or ketal function; or (2)N-derivatization, followed by treatment of the resultingper-N-protected-2''''-deoxy-3''''-desamino-2'''',3''''-epiminoaminoglycosidewith hydrogen in the presence of a catalyst, followed by acid hydrolysisof any acetal or ketal function and alkaline hydrolysis of saidN-protecting groups; or (3) N-derivatization followed by quaternizationwith a benzyl halide of the epimino function, treatment of the resultingper-N-protected-2''''-deoxy-3''''-desamino-2'''',3''''-(N-methyl-N-benzyl)epiminoaminoglycoside quaternary halide salt with hydrogen in thepresence of a cAtalyst followed by acid hydrolysis of any ketal oracetal functions and alkaline hydrolysis of said N-protecting groups; or(4) treatment with a sulfur nucleophile whereby is obtained a productmixture comprising a 2''''-deoxy-2''''-sulfhydryl-aminoglycoside and a2''''-deoxy-3''''-desamino-2''''-epi-amino-3''''-epi-sulfhydryl-aminoglycosideor thiol hydrocarbon ether or thiol alkanoyl ester derivatives thereofwherein said hydrocarbon and said alkanoyl have up to 8 carbon atoms,followed by desulfurization of said product mixture and acid hydrolysisof any acetal or ketal functions or alternatively, followed bydesulfurization of a per-N-protected derivative of said product mixture,thence acid hydrolysis of any ketal or acetal function followed byalkaline hydrolysis of said N-protecting groups; whereby is obtained aproduct mixture comprising a 2''''-deoxyaminoglycoside and a2''''-deoxy-3''''-desamino-2''''-epi-aminoglycoside.
 34. The processaccording to claim 33 wherein said antibacterially active4,6-di-(aminoglycosyl)-2-deoxystreptamine having a 2''''-hydroxy groupis a member selected from the group consisting of sisomicin, verdamicin,tobramycin, 3'',4''-dideoxykanamycin B, Antibiotic JI-20-A, AntibioticJI-20-B, Antibiotic G-418, and a gentamicin selected from the groupconsisting of gentamicin A, gentamicin B, gentamicin B1, gentamicin C1,gentamicin C1a, gentamicin C2, gentamicin C2a, gentamicin X2 andmixtures thereof, and wherein any protectable hydroxyl groups areprotected by an O-isopropylidene function.
 35. The process according toclaim 33 wherein said hydrocarbonsulfonyl halide in a tertiary amine ismethanesulfonyl chloride in pyridine; wherein said carbobenzyloxy groupsare removed from said2''''-O-methanesulfonyl-per-N-carbobenzyloxyaminoglycoside by treatmentwith hydrogen in the presence of palladium-on-charcoal; and said2''''-O-methanesulfonylaminoglycoside is converted to said2''''-deoxy-3''''-desmethylamino-2'''',3''''-epimino-aminoglycosideintermediate by heating said 2''''-O-methanesulfonylaminoglycoside inethanol at reflux temperature in the presence of sodium methoxide andwherein said 2''''-deoxy-3''''-desamino-2'''',3''''epimino-aminoglycoside is hydrogenolyzed by treatment in ethanol withhydrogen in the presence of Raney Nickel.
 36. The process according toclaim 33 wherein said antibacterially active4,6-di-(aminoglycosyl)-2-deoxystreptamine having a 2''''-hydroxyfunction is gentamicin C2; wherein said hydrocarbonsulfonyl halide in atertiary amine is methanesulfonyl chloride in pyridine; wherein saidcarbobenzyloxy groups are removed from said2''''-O-methanesulfonyl-per-N-carbobenzyloxygentamicin C2 by treatmentin ethanol with hydrogen in the presence of palladium-on-charcoal; and,wherein the thereby formed 2''''-O-methanesulfonylgentamicin C2spontaneously converts to2''''-deoxy-3''''-desmethylamino-2'''',3''''-N-methylepiminogentamicinC2.